Update actions/checkout action to v5 (#22)

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

Author: renovate[bot]

.github/workflows/gradle.yml

@@ -23,7 +23,7 @@ jobs:
       contents: read
 
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
       - name: Set up JDK 21
         uses: actions/setup-java@v4
         with: