Update actions/checkout action to v6

Author: renovate[bot]

.github/workflows/ci.yml

@@ -7,7 +7,7 @@ jobs:
   build:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v5
+      - uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6
         with:
           fetch-depth: 0
       - uses: actions/setup-java@v5
@@ -29,7 +29,7 @@ jobs:
     if: ${{ github.ref == 'refs/heads/main' || startswith(github.ref, 'refs/tags/') }}
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v5
+      - uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6
         with:
           fetch-depth: 0
       - uses: actions/setup-java@v5