Outdated spring-boot-maven-plugin build-info documentation causing project builds to fail

[bonii-xx]

With this PR the maven.compiler.source and maven.compiler.target properties were removed.

However, they are still used in the build-info section of the maven plugin, which means any project using the setup from the documentation got broken builds starting with 3.1.X.

Currently it's unclear what should be used instead (probably java.version or maven.compiler.release?) and the current documentation snippet causes builds to fail. Some migration info for anybody using this setup right now would probably also be helpful.

Documentation Pages with outdated info:

• https://github.com/spring-projects/spring-boot/blob/main/spring-boot-project/spring-boot-tools/spring-boot-maven-plugin/src/docs/asciidoc/build-info.adoc
• https://github.com/spring-projects/spring-boot/blob/main/spring-boot-project/spring-boot-tools/spring-boot-maven-plugin/src/docs/maven/build-info/pom.xml

[wilkinsona]

Thanks for spotting and reporting this, @bonii-xx. The need for a documentation update was mentioned on the PR but it looks like it wasn't acted upon.

The release notes mention that maven.compiler.release is now configured but not the removal of source and target. Once we've figured out what to use instead, we should update the release notes by adding a section to the upgrade instructions.

[mhalbritter]

I've updated the release notes: https://github.com/spring-projects/spring-boot/wiki/Spring-Boot-3.1-Release-Notes#switch-to-mavencompilerrelease