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](https://github.com/actions/checkout/compare/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>

Closes #1 /home/kupietz/KorAP/korapxmltool/.git/COMMIT_EDITMSG

Change-Id: I37e1ff9102c0fb592cb5f26a260142c46d2608f7
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 131f2e4..071a1ed 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -10,7 +10,7 @@
   build:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
       - name: Set up JDK 21
         uses: actions/setup-java@v5
         with:
diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
index 6c51b0d..9958206 100644
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -9,7 +9,7 @@
   release:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
       - name: Set up JDK 21
         uses: actions/setup-java@v5
         with: