Update actions/checkout action to v6 (#940)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

.github/workflows/codeql.yml

@@ -24,7 +24,7 @@ jobs:
 
     steps:
       - name: Checkout
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Initialize CodeQL
         uses: github/codeql-action/init@v4

.github/workflows/label-commenter.yml

@@ -12,7 +12,7 @@ jobs:
   comment:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         with:
           ref: master
       - name: Label Commenter

.github/workflows/linter.yml

@@ -6,7 +6,7 @@ jobs:
   linter:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v5
+    - uses: actions/checkout@v6
     - name: Use Node.js
       uses: actions/setup-node@v6
     - name: Install Dependencies

.github/workflows/npm-publish.yml

@@ -12,7 +12,7 @@ jobs:
       contents: write
       id-token: write
     steps:
-    - uses: actions/checkout@v5
+    - uses: actions/checkout@v6
     - name: Use Node.js
       uses: actions/setup-node@v6
       with:

.github/workflows/tester.yml

@@ -10,7 +10,7 @@ jobs:
         os: [ubuntu-latest, windows-latest, macos-latest]
       fail-fast: false
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         with:
           repository: hexojs/hexo-starter
       - name: Use Node.js
@@ -19,10 +19,10 @@ jobs:
         run: npm install
       - name: Install hexo-tag-embed
         run: npm install hexo-tag-embed
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         with:
           path: themes/next
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         with:
           repository: hexojs/hexo-many-posts
           path: source/_posts/hexo-many-posts