🐛 Fix malformed include directories in exported nlohmann_json CMake targets for component-based installs (#1662)

[burgholzer]

Description

This PR fixes the problems observed with the 3.5.0 release while updating in dependent MQT repositories.
There was a malformed include directory install command, that did not even turn out to be necessary (through local testing with QCEC, QMAP, and DDSIM).

This is essentially the forward port of #1662 and the v3.5.1 release.

Checklist

• The pull request only contains commits that are focused and relevant to this change.
• I have added appropriate tests that cover the new/changed functionality.
• I have updated the documentation to reflect these changes.
• I have added entries to the changelog for any noteworthy additions, changes, fixes, or removals.
• I have added migration instructions to the upgrade guide (if needed).
• The changes follow the project's style guidelines and introduce no new warnings.
• The changes are fully tested and pass the CI checks.
• I have reviewed my own code changes.

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  Guidelines.
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ℹ️ Review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: ASSERTIVE

Plan: Pro

Run ID: d8628526-ff5d-4fcd-a954-49a65492d21f

📥 Commits

Reviewing files that changed from the base of the PR and between f0d49c3 and 21ecb98.

📒 Files selected for processing (2)

• CHANGELOG.md
• UPGRADING.md

📝 Walkthrough

Walkthrough

Version 3.5.1 patch release is documented with a CMake packaging fix for nlohmann_json exports affecting find_package(mqt-core CONFIG). Upgrade guides are added for versions 3.5.1 and 3.4.0, and CMake installation logic for nlohmann_json is simplified by removing redundant target installation directives.

Changes

Cohort / File(s)	Summary
Release documentation CHANGELOG.md, UPGRADING.md	Added v3.5.1 release notes with CMake packaging fix, v3.4.0 ABI/SOVERSION guidance, and updated GitHub compare links.
CMake packaging cmake/ExternalDependencies.cmake	Simplified nlohmann_json installation by removing explicit header handling from install(TARGETS ...) command; separate header directory installation remains unchanged.

Estimated code review effort

🎯 1 (Trivial) | ⏱️ ~4 minutes

Possibly related PRs

• PR #1247: Addresses CMake packaging and installation of nlohmann_json to resolve find_package(mqt-core CONFIG) discovery issues.

Suggested labels

packaging

Poem

🐰 A rabbit's ode to orderly exports:
Release notes neat, the versions aligned,
CMake's redundant calls, simplified and refined,
nlohmann_json headers now neatly installed,
The package is tidy—configuration enthralled!

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title accurately describes the main fix: correcting malformed include directories in exported nlohmann_json CMake targets for component-based installs, with specific issue reference.
Description check	✅ Passed	The description covers the core issue, provides context about the 3.5.0 problems, mentions local testing validation, and includes a completed checklist with all required items marked.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

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✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch fix-component-based-install

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Actionable comments posted: 1

Caution

Some comments are outside the diff and can’t be posted inline due to platform limitations.

⚠️ Outside diff range comments (1)

UPGRADING.md (1)

242-248: ⚠️ Potential issue | 🟡 Minor

Missing version compare link for [3.5.1].

The [unreleased] link still points to v3.5.0...HEAD, and there is no [3.5.1] link definition in this file. Since the document now references ## [3.5.1], the compare link should be added and [unreleased] updated to start from v3.5.1 for the rendered links to resolve.

📝 Proposed fix

-[unreleased]: https://github.com/munich-quantum-toolkit/core/compare/v3.5.0...HEAD
+[unreleased]: https://github.com/munich-quantum-toolkit/core/compare/v3.5.1...HEAD
+[3.5.1]: https://github.com/munich-quantum-toolkit/core/compare/v3.5.0...v3.5.1
 [3.5.0]: https://github.com/munich-quantum-toolkit/core/compare/v3.4.0...v3.5.0

🤖 Prompt for AI Agents

Verify each finding against the current code and only fix it if needed.

In `@UPGRADING.md` around lines 242 - 248, Update the link definitions at the
bottom so the `[unreleased]` and new `[3.5.1]` references resolve: change
`[unreleased]` to start from `v3.5.1...HEAD` instead of `v3.5.0...HEAD`, and add
a new `[3.5.1]:` compare link (e.g.,
`https://github.com/munich-quantum-toolkit/core/compare/v3.5.0...v3.5.1`) so the
existing `## [3.5.1]` heading renders correctly.

🤖 Prompt for all review comments with AI agents

Verify each finding against the current code and only fix it if needed.

Inline comments:
In `@CHANGELOG.md`:
- Around line 364-365: The changelog defines an unused markdown reference
`[`#1654`]`; remove the dangling link definition `[`#1654`]:
https://github.com/munich-quantum-toolkit/core/pull/1654` from the bottom of the
CHANGELOG.md or instead add the missing changelog entry that uses `[`#1654`]` in
the body so the reference is consumed; locate the `[`#1654`]` link definition and
either delete that line or insert the corresponding release note that references
`[`#1654`]`.

---

Outside diff comments:
In `@UPGRADING.md`:
- Around line 242-248: Update the link definitions at the bottom so the
`[unreleased]` and new `[3.5.1]` references resolve: change `[unreleased]` to
start from `v3.5.1...HEAD` instead of `v3.5.0...HEAD`, and add a new `[3.5.1]:`
compare link (e.g.,
`https://github.com/munich-quantum-toolkit/core/compare/v3.5.0...v3.5.1`) so the
existing `## [3.5.1]` heading renders correctly.

🪄 Autofix (Beta)

Fix all unresolved CodeRabbit comments on this PR:

• Push a commit to this branch (recommended)
• Create a new PR with the fixes

---

ℹ️ Review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: ASSERTIVE

Plan: Pro

Run ID: 79448dda-1af1-4575-87e4-76262d9df1f3

📥 Commits

Reviewing files that changed from the base of the PR and between 6959a5e and f0d49c3.

📒 Files selected for processing (3)

• CHANGELOG.md
• UPGRADING.md
• cmake/ExternalDependencies.cmake

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.

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