toolVersion property is not considered input for cache/up-to-date checks

[davidburstrom]

Changing the toolVersion will not force the SpotBugs plugin to execute the tasks again. This can be problematic for example when bumping SpotBugs version automatically in CI, where new detectors won't flag newly discovered issues. The provided zip-file is a standalone project that reproduces the issue. This happens on all tested versions of the SpotBugs Gradle plugin, even the latest.

1. Run ./gradlew :spotbugsMain, it will pass correctly.
2. Change toolVersion to "4.8.3"
3. Run ./gradlew :spotbugsMain, it will pass incorrectly.
4. Run ./gradlew :spotbugsMain --rerun-tasks, it will fail correctly.
5. Run ./gradlew :spotbugsMain, it will fail correctly.

Seemingly, the problem is that the tool version property is not propagated as task input in any way, either as-is or as part of a classpath.

spotbugs-gradle-plugin-toolversion-input-bug.zip