ci: pin Integration Test to Temurin 17 - #3780

Description

Fixes #3779

The Integration Test job uses ubuntu-latest and does not call actions/setup-java. After the hosted image moved from ubuntu-24.04 (Temurin 17) to ubuntu-26.04 (Temurin 25), that job is cancelled at timeout-minutes: 30. The Java client in java_interop/service_discovery/service throws NoClassDefFoundError: com/alibaba/fastjson/JSONException from Dubbo 3.3.6 JsonUtils.loadExtensions (hasNext() is outside the try) and mvn exec:java does not return.

This pull request adds actions/setup-java@v4 (temurin, 17, cache: maven) to that job only, before ./integrate_test.sh. The step matches dubbo-go-samples CI. cache: maven is safe here because develop contains tools/benchmark/server/dubbo-java/pom.xml, so setup-java has a pom to hash. The Unit Test job is unchanged and still uses Temurin 8 for the ZooKeeper fatjar. No Go source is changed. Release artifacts are unchanged.

Severity: CI blocker for Integration Test on every pull request since the image move. It is not a user-runtime bug and not a release-artifact bug.

Impact:

• Last green Integration Test: https://github.com/apache/dubbo-go/actions/runs/39560565003 (Image: ubuntu-24.04, java.home=/usr/lib/jvm/temurin-17-jdk-amd64, Maven 3.10.0). The service sample printed Greeting:Mamba!!!!!!!!!!!! at 09:07:29Z and > ok at 09:08:35Z.
• First cancel: https://github.com/apache/dubbo-go/actions/runs/39619613061 (Image: ubuntu-26.04, java.home=/usr/lib/jvm/temurin-25-jdk-amd64, Maven 3.9.15, Thread.java:1474). Error at 05:19:28Z, ##[error]The operation was canceled at 05:28:40Z.
• Same Integration Test cancel, with Unit Test and Check License Header green: https://github.com/apache/dubbo-go/actions/runs/39757462666, https://github.com/apache/dubbo-go/actions/runs/40038682961 (fix(router): load initial application rules and handle omitted flags #3773), https://github.com/apache/dubbo-go/actions/runs/40082838939 (fix(jsonrpc): avoid infinite recursion in serverRequest.UnmarshalJSON under encoding/json v2 #3778).
• The two heads around the break (917f692f and 8ff7866c) differ only in .github/workflows/tools.yml.

Root cause and the non-exiting client are written up in #3779. apache/dubbo#15754 fixes JsonUtils on branch 3.3 and is not in the 3.3.6 release. Maven Central org.apache.dubbo:dubbo latest is still 3.3.6, so the samples pom has no fixed version to move to. This repository should pin the JDK the samples were green on.

Why not dubbo-go-samples: that repository's CI already pins Temurin 17. This job never calls setup-java, so it keeps the image JDK. Changing samples would not select the JDK for this job.

This is separate from the Go 1.27 leak. apache/skywalking-eyes/header@main (7f98a36a) sets go-version: "1.27", and in this repository that action is only the Check License Header job. On run 40082838939 that job logs go version go1.27.3, while Integration Test logs Setup go version spec 1.25.0 and go version go1.25.0. The jsonrpc crash under encoding/json v2 is #3777 / #3778. It did not cancel these Integration Test jobs.

Merge order:

1. Merge this pull request first, so later pull request runs pick up Temurin 17. Re-running fix(jsonrpc): avoid infinite recursion in serverRequest.UnmarshalJSON under encoding/json v2 #3778's existing run 40082838939 will not: a re-run keeps that run's workflow file, which has no setup-java. fix(jsonrpc): avoid infinite recursion in serverRequest.UnmarshalJSON under encoding/json v2 #3778 needs a new run after this change is on develop (update the branch). Its Integration Test failure is this JDK 25 cancel. That job's Go is 1.25.0, and its Unit Test job already succeeded.
2. Then merge fix(jsonrpc): avoid infinite recursion in serverRequest.UnmarshalJSON under encoding/json v2 #3778, which fixes [Bug]: jsonrpc server crashes while decoding a request under Go 1.27 encoding/json v2 #3777 for Go 1.27 callers.
3. samples, independently: merge ci: run the license-header check before setting up Go dubbo-go-samples#1156 first (Build And Integration passed on https://github.com/apache/dubbo-go-samples/actions/runs/40082624365). Then update test(observability): add reproducible signal captures dubbo-go-samples#1155. Run https://github.com/apache/dubbo-go-samples/actions/runs/40075757874 prints go1.25.0 at "Check tool versions", go1.27.3 inside "Check license header", and then the jsonrpc server refuses connections. samples CI already has Temurin 17, so that failure is the Go 1.27 leak, not JDK 25.

make fmt, make test, and a new Go test are not run. The diff is this workflow file only. The check that this pin works is the Integration Test job on this pull request.

Checklist

• I confirm the target branch is develop
• I have run make fmt to format my code
• I have run make test to run local tests
• I have added tests that prove my fix is effective or that my feature works