Add composer package cache in CI

.github/workflows/ci.yml

@@ -9,6 +9,15 @@ jobs:
           php-version: '8.0'
           coverage: xdebug
       - uses: actions/checkout@v2
+      - name: Get composer cache directory
+        id: composer-cache
+        run: echo "::set-output name=dir::$(composer config cache-files-dir)"
+      - name: Cache dependencies
+        uses: actions/cache@v2
+        with:
+          path: ${{ steps.composer-cache.outputs.dir }}
+          key: ${{ runner.os }}-composer-${{ hashFiles('**/composer.lock') }}
+          restore-keys: ${{ runner.os }}-composer-
       - name: Install dependencies
         run: composer install --no-progress --no-interaction
       - name: Generate app key