chore(deps): update actions/checkout action to v6

Author: renovate[bot]

.github/workflows/build.yml

@@ -19,7 +19,7 @@ jobs:
     permissions:
       contents: write
     steps:
-    - uses: actions/checkout@v5
+    - uses: actions/checkout@v6
       with:
         fetch-depth: 0
     - 

.github/workflows/check.yml

@@ -7,7 +7,7 @@ jobs:
     name: shellcheck
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - name: Run ShellCheck
         uses: ludeeus/action-shellcheck@master
 env: