Fix CI

Author: ashtanko

.github/workflows/ci.yml

@@ -27,7 +27,7 @@ jobs:
         run: flutter --version
 
       - name: Cache pub dependencies
-        uses: actions/cache@v2
+        uses: actions/cache@v4
         with:
           path: ${{ env.FLUTTER_HOME }}/.pub-cache
           key: ${{ runner.os }}-pub-${{ hashFiles('**/pubspec.lock') }}