Update actions/checkout action to v6

Author: renovate[bot]

.github/workflows/ci.yml

@@ -12,7 +12,7 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-      - uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5
+      - uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6
 
       - name: Set up JDK 21
         uses: actions/setup-java@dded0888837ed1f317902acf8a20df0ad188d165 # v5

.github/workflows/release.yml

@@ -44,7 +44,7 @@ jobs:
           java-version: 21
 
       - name: Checkout
-        uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5
+        uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6
         with:
           token: ${{ secrets.REPO_ACCESS_TOKEN }}