Replace deprecated set-output command

Author: JulianVennen

Diff for: .github/workflows/tests.yaml

@@ -28,12 +28,12 @@ jobs:
 
       - name: Set composer cache directory
         id: composer-cache
-        run: echo "::set-output name=dir::$(composer config cache-files-dir)"
+        run: echo "COMPOSER_CACHE_DIRECTORY=$(composer config cache-files-dir)" >> $GITHUB_ENV
 
       - name: Restore composer from cache
         uses: actions/cache@v3
         with:
-          path: ${{ steps.composer-cache.outputs.dir }}
+          path: ${{ env.COMPOSER_CACHE_DIRECTORY }}
           key: ${{ runner.os }}-composer-${{ hashFiles('**/composer.lock') }}
           restore-keys: ${{ runner.os }}-composer-