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

Author: renovate[bot]

.github/workflows/rebase.yml

@@ -16,7 +16,7 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-      - uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v5
+      - uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6
       - uses: ljharb/rebase@3f30d8c115145dcc562f01582f59fbeefe77c707 # @master
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}