build(deps): 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] <support@github.com>

Author: dependabot[bot]

.github/workflows/benchmark.yml

@@ -12,7 +12,7 @@ jobs:
       contents: write
 
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
 
       - name: Set up Azul Zulu JDK 25
         uses: actions/setup-java@v5

.github/workflows/ci.yml

@@ -15,7 +15,7 @@ jobs:
         java-version: [ '25', '26' ]
 
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
 
       - name: Set up Azul Zulu JDK ${{ matrix.java-version }}
         uses: actions/setup-java@v5

.github/workflows/publish.yml

@@ -13,7 +13,7 @@ jobs:
     runs-on: ubuntu-latest
     environment: maven
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
 
       - name: Set up JDK 25 with Maven Central publishing
         uses: actions/setup-java@v5