Update actions/checkout action to v6 (#59)

Co-authored-by: horothesun-renovate[bot] <155104562+horothesun-renovate[bot]@users.noreply.github.com>

Author: horothesun-renovate[bot]

.github/workflows/ci.yml

@@ -15,7 +15,7 @@ jobs:
     runs-on: ubuntu-latest
     timeout-minutes: 1
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
 
       - name: Run ShellCheck
         uses: ludeeus/[email protected]
@@ -29,7 +29,7 @@ jobs:
     runs-on: ubuntu-latest
     timeout-minutes: 3
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
 
       - name: Get JDK version
         run: |
@@ -50,7 +50,7 @@ jobs:
     runs-on: ubuntu-latest
     timeout-minutes: 1
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
 
       - name: Get JDK version
         run: |
@@ -71,7 +71,7 @@ jobs:
     runs-on: ubuntu-latest
     timeout-minutes: 3
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
 
       - name: Build Dockerfile
         run: docker build --file "./Dockerfile" "."