Bump actions/checkout from 5 to 6 (#46)

Author: dependabot[bot]

.github/workflows/docker.yml

@@ -26,7 +26,7 @@ jobs:
       packages: write
 
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - uses: docker/setup-qemu-action@v3
       - uses: docker/setup-buildx-action@v3
       - uses: docker/login-action@v3