[CI]: Bump actions/checkout from 5 to 6 in the ci-actions group

Bumps the ci-actions group with 1 update: [actions/checkout](https://github.com/actions/checkout).


Updates `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
  dependency-group: ci-actions
...

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

Author: dependabot[bot]

.github/workflows/build-kdoc.yml

@@ -14,7 +14,7 @@ jobs:
     name: Build and publish KDoc
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - uses: actions/setup-java@v5
         with:
           distribution: temurin

.github/workflows/codeql.yml

@@ -27,7 +27,7 @@ jobs:
 
     steps:
     - name: Checkout repository
-      uses: actions/checkout@v5
+      uses: actions/checkout@v6
     - uses: actions/setup-java@v5
       with:
         distribution: temurin

.github/workflows/test-dev.yml

@@ -9,7 +9,7 @@ jobs:
     name: Tests without emulator
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - uses: actions/setup-java@v5
         with:
           distribution: temurin
@@ -24,7 +24,7 @@ jobs:
     name: Tests with emulator
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - uses: actions/setup-java@v5
         with:
           distribution: temurin