chore(deps): update actions/checkout action to v6 (#764)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

.github/workflows/main.yml

@@ -28,7 +28,7 @@ jobs:
       matrix:
         java-version: [21, 24]
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         with:
           submodules: 'true'
 

.github/workflows/release.yml

@@ -50,7 +50,7 @@ jobs:
             exit 1
           fi
 
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         with:
           fetch-depth: '0'
           submodules: 'true'