Merge pull request #148 from goaop/copilot/fix-147

Update GitHub Actions to fix CI build failures

Author: lisachenko

.github/workflows/phpunit.yml

@@ -23,7 +23,7 @@ jobs:
 
     steps:
       - name: "Checkout"
-        uses: "actions/checkout@v2"
+        uses: "actions/checkout@v4"
 
       - name: "Install PHP"
         uses: "shivammathur/setup-php@v2"
@@ -34,7 +34,7 @@ jobs:
           tools: composer:v2, cs2pr
 
       - name: "Cache dependencies"
-        uses: "actions/cache@v2"
+        uses: "actions/cache@v4"
         with:
           path: |
             ~/.composer/cache