Update actions/checkout action to v7

Author: renovate[bot]

.github/workflows/run_gradle_task.yml

@@ -64,7 +64,7 @@ jobs:
       ### Gradle task ###
 
       - name: Checkout the repo
-        uses: actions/checkout@v6
+        uses: actions/checkout@v7
         with:
           ref: ${{ inputs.checkout-ref || github.ref }}