chore(deps): update actions/checkout action to v6

.gitea/workflows/build-and-push.yaml

@@ -14,7 +14,7 @@ jobs:
     steps:
       # Checkout the repository code
       - name: Checkout repository
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Set outputs
         id: vars
@@ -55,7 +55,7 @@ jobs:
     if: ${{ success() }}
     steps:
       - name: Checkout target repository
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
         with:
           repository: infrastructure/core-apps
           token: ${{ secrets.ACTIONS_TOKEN }}