Fix CI deprecation

Author: francislavoie

.github/workflows/ci.yml

@@ -33,8 +33,8 @@ jobs:
           COMPOSER_TOKEN: ${{ secrets.GITHUB_TOKEN }}
 
       - name: Get composer cache directory
-        id: composercache
-        run: echo "::set-output name=dir::$(composer config cache-files-dir)"
+        id: composer_cache
+        run: echo "dir=$(composer config cache-files-dir)" >> $GITHUB_OUTPUT
 
       - name: Setup problem matchers
         run: |
@@ -44,7 +44,7 @@ jobs:
       - name: Cache composer dependencies
         uses: actions/cache@v2
         with:
-          path: ${{ steps.composercache.outputs.dir }}
+          path: ${{ steps.composer_cache.outputs.dir }}
           key: ${{ runner.os }}-composer-${{ hashFiles('**/composer.lock') }}
           restore-keys: ${{ runner.os }}-composer-