Update actions/checkout action to v6

Author: renovate[bot]

.github/workflows/deploy.yml

@@ -20,7 +20,7 @@ jobs:
     steps:
 
       - name: Check out the repo
-        uses: actions/checkout@v2
+        uses: actions/checkout@v6
 
       - name: Cache Docker layers
         uses: actions/cache@v2