[workflow]: 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/build.yml

@@ -14,7 +14,7 @@ jobs:
         os: [ubuntu-latest]
 
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - name: Set up Java
         uses: actions/setup-java@v5
         with:

.github/workflows/jdk-ea-stable.yml

@@ -16,7 +16,7 @@ jobs:
       packages: write
 
     steps:
-    - uses: actions/checkout@v5
+    - uses: actions/checkout@v6
     - name: Set up Java
       uses: oracle-actions/setup-java@v1
       with:

.github/workflows/jdk-ea.yml

@@ -21,7 +21,7 @@ jobs:
         os: [ubuntu-latest]
 
     steps:
-    - uses: actions/checkout@v5
+    - uses: actions/checkout@v6
     - name: Set up Java
       uses: oracle-actions/setup-java@v1
       with: