Error Prone 2.31.0

This is the last planned minor release of Error Prone that will support running on JDK 11, see #3803. Using Error Prone to compile code that is deployed to earlier versions will continue to be fully supported, but will require using JDK 17 or newer for compilation and setting --release or -source/-target/-bootclasspath.

Changes:

• Introduce @ThreadSafeTypeParameter with enforcement by ThreadSafe
• Improved support for latest JDK 24 EA builds
• Error Prone is now distributed as a Multi-Release jar (#3756)

New checks:

• AutoValueBoxedValues: AutoValue instances should not usually contain boxed types that are not Nullable. We recommend removing the unnecessary boxing.

Full changelog: v2.30.0...v2.31.0