update to checkout v4

Author: freddycoder

.github/workflows/push-to-docker-hub.yml

@@ -25,7 +25,7 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
 
       # Login into acr
       - name: Login into ACR