[Chore] Bump version to 4.2.1

[JiahuiWho]

Description

This bumps the version to 4.2.1

Context

Patch release

Testing

• ./gradlew test

Documentation

N/A

Known limitations

N/A

[Copilot]

Pull request overview

Bumps the project/package version to 4.2.1 for a patch release.

Changes:

• Updated Gradle project version to 4.2.1.
• Updated runtime/version metadata to 4.2.1.
• Updated README Docker badge/link to point at the 4.2.1 tag.

Reviewed changes

Copilot reviewed 2 out of 3 changed files in this pull request and generated no comments.

File	Description
service-runner/src/main/resources/version-info.properties	Updates embedded version metadata to 4.2.1.
README.md	Updates the Docker “Latest Release” badge/link to 4.2.1.
build.gradle.kts	Updates Gradle allprojects version to 4.2.1.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.