fix github action

Author: biczomate

.github/workflows/ci.yml

@@ -33,6 +33,8 @@ jobs:
         with:
           java-version: '8'
           distribution: 'temurin'
+      - name: Make gradlew executable
+        run: chmod +x ./gradlew
       - name: Build with Gradle
         uses: gradle/gradle-build-action@bd5760595778326ba7f1441bcf7e88b49de61a25 # v2.6.0
         with: