Update gha workflow

Author: danmichaelo

.github/workflows/main.yml

@@ -13,7 +13,7 @@ jobs:
     runs-on: ubuntu-latest
     name: PHP ${{ matrix.php }}
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v3
     - uses: php-actions/composer@v6
       with:
         php_version: ${{ matrix.php }}