chore: update actions/checkout action to v6

Author: renovate[bot]

.github/workflows/ci.yml

@@ -15,7 +15,7 @@ jobs:
 
     steps:
       - name: Checkout code
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Setup Node.js ${{ matrix.node-version }}
         uses: actions/setup-node@v6
@@ -42,7 +42,7 @@ jobs:
 
     steps:
       - name: Checkout code
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Setup Node.js
         uses: actions/setup-node@v6

.github/workflows/release.yml

@@ -13,7 +13,7 @@ jobs:
 
     steps:
       - name: Checkout code
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Setup Node.js
         uses: actions/setup-node@v6

.github/workflows/update-dependencies.yml

@@ -22,7 +22,7 @@ jobs:
 
     steps:
       - name: Checkout
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Self-hosted Renovate
         uses: renovatebot/github-action@v44.2.6