Fix: update actions/checkout to v4

Author: UHAsikakutou

content/intro-to-storybook/react/ja/deploy.md

@@ -94,7 +94,7 @@ jobs:
     runs-on: ubuntu-latest
     # Job steps
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
         with:
           fetch-depth: 0
       - run: yarn