Update GitHub Action versions (#347)

Author: TimWolla

.github/workflows/ci.yml

@@ -10,7 +10,7 @@ jobs:
 
     steps:
     - name: Checkout
-      uses: actions/checkout@v1
+      uses: actions/checkout@v5
 
     - name: Setup PHP
       uses: shivammathur/setup-php@v2
@@ -19,7 +19,7 @@ jobs:
         tools: "cs2pr"
 
     - name: "Cache dependencies installed with composer"
-      uses: "actions/cache@v1"
+      uses: "actions/cache@v4"
       with:
         path: "~/.composer/cache"
         key: "php-${{ matrix.php-version }}-composer-locked-${{ hashFiles('composer.lock') }}"