Releasing KeY 3.0 and 2.13 release (Milestone v3.0.0)

[wadoon]

This issue is an umbrella for the main tasks involved in wrapping up the KeY 3.0 and 2.13 combined release milestone. It tracks sub-issues for specific deliverables needed for both the 3.0 and 2.13 releases.

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Release Plan Checklist for KeY 3.0 / KeY 2.13 Combined Release

1. Feature Freeze

• Community decision on readiness, agree on versions.
• Create version branches (key-3.0 and key-2.13) from main.
• Limit commits on release branches to bug fixes and documentation only—no new features.
• Create Pull Requests from key-3.0 and key-2.13 back to main post-release.
• Increment the version number on main after branching.

2. Testing

• Freeze and stabilize software on both release branches.
• Conduct thorough community and CI-driven testing.

3. Update Documentation

• Update the version number in README and related documentation for both versions.

4. Finalize the Software

• Tag the release candidates and final releases:

  git tag KeY-3.0.0
  git tag KeY-2.13.0

5. Changelog

• Compose/collect significant changes in key-docs changelog.
• Use changelog as the GitHub release description.

6. Build Artifacts

• Build distributions using:

  gradle clean assemble shadowJar --parallel

7. Create GitHub Releases

• Create releases for tags KeY-3.0.0 and KeY-2.13.0.
• Upload shadowJars: key-*-exe.jar, keyext.proofmanagement-*-exe.jar, key.removegenerics-*.jar.
• Use changelog as release description.

8. Deploy to Maven Central

• Publish using:

  gradle publish

  • (Do not use --parallel).
• Finalize and close staging repositories in Nexus (OSSRH instructions).

9. Announcements

• News entry on key-project.org.
• Announcement email to key-all@.

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Post-Release

• Merge bug fixes on release branches back into main.

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Announcement Email Template:

Dear friends of KeY,

It is our pleasure to present the new releases 3.0 and 2.13 of KeY, your
favourite Java verification application.

    https://github.com/KeYProject/key/releases/latest

Thanks to the effort of researchers and student assistants who invested
a great deal of work into KeY since the last release, we can now proudly
present new versions which

<some new fancy features>

Thanks for everyone's effort! Especially for the particular energy
invested during the last few weeks on last-minute fixes and polishes to
the tool. Thanks, Alexander and Wolfram for finalising the release.

Best regards,
   <name>