Fix: Update checkout action version to use master branch

Author: krugazul

.github/workflows/push-deploy.yml

@@ -9,7 +9,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout code
-        uses: actions/checkout@v6
+        uses: actions/checkout@master
 
       - name: WordPress Plugin Deploy
         uses: 10up/action-wordpress-plugin-deploy@stable