Upgrade actions/cache

Author: hlecorche

.github/workflows/tests.yml

@@ -57,7 +57,7 @@ jobs:
                 run: echo "::set-output name=dir::$(composer config cache-dir)"
 
             -   name: Cache dependencies
-                uses: actions/cache@v2
+                uses: actions/cache@v3
                 with:
                     path: ${{ steps.composer-cache.outputs.dir }}
                     key: composer-${{ runner.os }}-${{ matrix.php-version }}-${{ hashFiles('**/composer.*') }}-${{ matrix.composer-flags }}