ci(deps): bump actions/checkout from 5 to 6

Bumps [actions/checkout](https://github.com/actions/checkout) from 5 to 6.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@v5...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/update-syntaxes.yml

@@ -46,7 +46,7 @@ jobs:
 
 
     - name: Git Checkout
-      uses: actions/checkout@v5  # https://github.com/actions/checkout
+      uses: actions/checkout@v6  # https://github.com/actions/checkout
 
 
     - name: "Install: JDK ${{ env.JAVA_VERSION }} ☕"