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

Author: cq-bot

.github/workflows/lint_golang.yml

@@ -15,7 +15,7 @@ jobs:
     name: Lint with GolangCI
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - uses: actions/setup-go@v6
         with:
           go-version-file: go.mod

.github/workflows/lint_markdown.yml

@@ -14,7 +14,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Git checkout
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
       - name: Vale
         uses: errata-ai/vale-action@v2
         with:
@@ -26,7 +26,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Git checkout
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
       - name: markdownlint-cli
         uses: nosborn/[email protected]
         with:

.github/workflows/unittest.yml

@@ -23,7 +23,7 @@ jobs:
           git config --global core.autocrlf false
           git config --global core.eol lf
       - name: Check out code into the Go module directory
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
       - name: Set up Go 1.x
         uses: actions/setup-go@v6
         with: