Bump gradle/gradle-build-action from 2.11.1 to 2.12.0

Bumps [gradle/gradle-build-action](https://github.com/gradle/gradle-build-action) from 2.11.1 to 2.12.0.
- [Release notes](https://github.com/gradle/gradle-build-action/releases)
- [Commits](gradle/gradle-build-action@v2.11.1...v2.12.0)

---
updated-dependencies:
- dependency-name: gradle/gradle-build-action
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

.github/workflows/ci.yml

@@ -148,7 +148,7 @@ jobs:
           cache: gradle
 
       - name: Build
-        uses: gradle/gradle-build-action@v2.11.1 # v2.11.1
+        uses: gradle/gradle-build-action@v2.12.0 # v2.11.1
         with:
           gradle-version: 1.12
           build-root-directory: picocli-tests-java567/