Update actions/checkout action to v6

.gitea/workflows/docker-build.yaml

@@ -1,10 +1,10 @@
-name: Docker build and push
+name: Docker Build and Push
 
 on:
   pull_request:
-    branches: [master]
+    branches: [main]
   push:
-    branches: [master]
+    branches: [main]
   schedule:
     - cron: '0 0 * * *'
 
@@ -13,7 +13,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
 
       - name: Set up Docker Buildx
         uses: docker/setup-buildx-action@v3
@@ -34,7 +34,7 @@ jobs:
             type=ref,event=branch
             type=ref,event=pr
             type=sha
-            type=raw,value=latest,enable=${{ github.ref == 'refs/heads/master' }}
+            type=raw,value=latest,enable=${{ github.ref == 'refs/heads/main' }}
 
       - name: Build and push
         uses: docker/build-push-action@v6