ci: update CI workflow by removing unnecessary caching steps

.gitea/workflows/ci.yml

@@ -26,20 +26,12 @@ jobs:
           key: gradle-${{ runner.os }}-common
           restore-keys: |
             gradle-${{ runner.os }}-
-      - name: "Cache Gradle build outputs"
-        uses: actions/cache@v3
-        with:
-          path: backend/build
-          key: gradle-build-${{ runner.os }}-common
-          restore-keys: |
-            gradle-build-${{ runner.os }}-
       - name: "Prepare Gradle"
         working-directory: ./backend
         run: gradle clean
       - name: "Check"
         working-directory: ./backend
         run: gradle checkstyleMain
-      - run: find . -print | sed -e "s;[^/]*/;|____;g;s;____|; |;g"
       - name: "Stop Gradle"
         working-directory: ./backend
         run: gradle --stop