change wrapper permissions

Author: Guy Davenport

.github/workflows/generate-schema.yml

@@ -16,6 +16,8 @@ jobs:
           distribution: 'temurin'
       - name: Setup Gradle
         uses: gradle/actions/setup-gradle@v4
+      - name: Change wrapper permissions
+        run: chmod +x ./gradlew
       - name: Build with Gradle Wrapper
         working-directory: ./generator/
         run: ./gradlew validate