github actions update cache@v4.

Author: smeghead

.github/workflows/php.yml

@@ -27,7 +27,7 @@ jobs:
 
     - name: Cache Composer packages
       id: composer-cache
-      uses: actions/cache@v3
+      uses: actions/cache@v4
       with:
         path: vendor
         key: ${{ runner.os }}-php-${{ hashFiles('**/composer.lock') }}