ci: bump actions/checkout to v4

Author: checkout‑bot

.github/workflows/build.yml

@@ -10,7 +10,7 @@ jobs:
   build:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
 
       - name: Setup Node.js
         uses: actions/setup-node@v3

.github/workflows/format.yml

@@ -10,7 +10,7 @@ jobs:
   prettier:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
 
       - name: Setup Node.js
         uses: actions/setup-node@v3

.github/workflows/lint.yml

@@ -10,7 +10,7 @@ jobs:
   eslint:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
 
       - name: Setup Node.js
         uses: actions/setup-node@v3