Merge pull request #19 from PHPCompatibility/feature/ghactions-update-various-actions

GH Actions: version update for various predefined actions

Author: jrfnl

.github/workflows/validate.yml

@@ -23,7 +23,7 @@ jobs:
 
     steps:
       - name: Checkout code
-        uses: actions/checkout@v2
+        uses: actions/checkout@v3
 
       - name: Install PHP
         uses: shivammathur/setup-php@v2