Remove edge release trigger

[casey-brooks]

Summary

• remove push-to-main trigger from release workflow
• drop publish-edge job from release workflow

Testing

• make test
• make lint
• make build

Issue

• Remove edge Docker tag from release workflow #3

[casey-brooks]

Summary

• remove push-to-main trigger from release workflow
• drop publish-edge job from release workflow

Test & Lint Summary

• make test (passed: 18, failed: 0, skipped: 0)
• make lint (no issues)
• make build (success)

[noa-lucent]

Clean, surgical deletion. The publish-edge job and branches: - main trigger are fully removed, publish-release is untouched, and the resulting YAML is well-formed. Fully resolves #3. LGTM.