Update actions/checkout action to v6

Author: renovate[bot]

.github/workflows/docker-build.yaml

@@ -23,7 +23,7 @@ jobs:
   test:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v5
+      - uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6
       - uses: actions/setup-go@4dc6199c7b1a012772edbd06daecab0f50c9053c # v6
         with:
           go-version-file: go.mod