Backports the wrapper caching fix to the v5 release line.
The Maven wrapper distribution (~/.m2/wrapper/dists) and Gradle wrapper
distribution (~/.gradle/wrapper) were cached in the same entry as the
dependency cache, keyed on the volatile dependency-file hashes (**/pom.xml,
**/*.gradle*). With no restoreKeys fallback (#269), almost every dependency
change was a full cache miss, forcing ./mvnw and ./gradlew to re-download the
build tool distribution and hitting intermittent rate-limit failures.
Each wrapper distribution now lives in its own additional cache entry keyed
only on the rarely-changing wrapper properties file
(**/.mvn/wrapper/maven-wrapper.properties, **/gradle-wrapper.properties), so
it survives dependency changes. Optional-cache saves swallow ValidationError
and ReserveCacheError so a project without a wrapper never fails the post step.
Fixes: #1095
Copilot-Session: ea015caa-980a-4e0a-af20-3fc9f39c77fd
Co-authored-by: Copilot App <[email protected]>
