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

Author: renovate[bot]

.github/workflows/checks.yml

@@ -7,7 +7,7 @@ jobs:
   test:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v5
+      - uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6
       - uses: openapi-generators/openapi-python-client-action@v2
         with:
           openapi-url: https://raw.githubusercontent.com/openapi-generators/openapi-python-client/main/end_to_end_tests/baseline_openapi_3.0.json