ci: bump actions/checkout from 4 to 6 in the actions group

Bumps the actions group with 1 update: [actions/checkout](https://github.com/actions/checkout).


Updates `actions/checkout` from 4 to 6
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@v4...v6)

---
updated-dependencies:
- dependency-name: actions/checkout
  dependency-version: '6'
  dependency-type: direct:production
  update-type: version-update:semver-major
  dependency-group: actions
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

.github/workflows/ci.yml

@@ -30,7 +30,7 @@ jobs:
         uses: tree-sitter/parser-test-action@v2
 
       - name: Clone apisix corpus
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
         with:
           path: examples/apisix
           repository: apache/apisix
@@ -111,7 +111,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Set up repository
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
 
       - name: Set up tree-sitter
         uses: tree-sitter/setup-action@v2