Bump actions/checkout from 4 to 6

Bumps [actions/checkout](https://github.com/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
...

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

Author: dependabot[bot]

.github/workflows/benchmark.yml

@@ -211,7 +211,7 @@ jobs:
         name: Deploy the website to a specific folder
         if: ${{ github.event.inputs.upload_id != '' || github.event.client_payload.upload_id != '' }}
         steps:
-            -   uses: actions/checkout@v5
+            -   uses: actions/checkout@v6
 
             -   uses: astral-sh/setup-uv@v5
 

.github/workflows/ci.yml

@@ -67,7 +67,7 @@ jobs:
     needs: build_wheel
     if: "!contains(github.event.head_commit.message, 'integration_tests skip')"
     steps:
-    - uses: actions/checkout@v4
+    - uses: actions/checkout@v6
 
     - uses: astral-sh/setup-uv@v5