Bump actions/checkout from 5 to 6 (#159)

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

.github/workflows/maven-publish.yml

@@ -10,7 +10,7 @@ jobs:
     permissions:
       contents: write
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
 
       - name: Generate changelog
         id: changelog

.github/workflows/maven.yml

@@ -10,7 +10,7 @@ jobs:
   build:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - name: Set up JDK 21
         uses: actions/setup-java@v5
         with: