Update actions/checkout action to v6

Author: renovate[bot]

.github/workflows/build.yaml

@@ -14,7 +14,7 @@ jobs:
   build:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
       - name: Set up QEMU
         uses: docker/setup-qemu-action@v3
       - name: Set up Docker Buildx

.github/workflows/docker-hub-stats.yaml

@@ -8,7 +8,7 @@ jobs:
   build:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
       - name: Get docker hub stats via script
         run: bash script/docker-hub-stats.sh
       - uses: stefanzweifel/git-auto-commit-action@v5