Use actions/cache@v4

Author: bytehead

.github/workflows/ci.yml

@@ -84,7 +84,7 @@ jobs:
                 uses: actions/checkout@v3
 
             -   name: Setup cache
-                uses: actions/cache@v2
+                uses: actions/cache@v4
                 id: cache-db
                 with:
                     path: ~/.symfony/cache