fix(ci): include gradle-wrapper.jar for CI builds

Add exception in .gitignore to allow gradle-wrapper.jar which is
required for the Groovy compilation step in GitHub Actions.

The Gradle Wrapper JAR must be committed to ensure reproducible
builds across all environments.

Author: laugiov

.gitignore

@@ -8,6 +8,7 @@ __pycache__/
 dist/
 build/
 *.jar
+!**/gradle-wrapper.jar
 *.war
 target/
 .gradle/