Update GitHub Actions versions in ci.yml and doc.yml

Author: kojix2

.github/workflows/ci.yml

@@ -9,7 +9,7 @@ jobs:
         os:   [ 'ubuntu', 'macos' ]
         ruby: [ '2.6', '2.7', '3.0', '3.1', '3.2', '3.3' ]
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - uses: ruby/setup-ruby@v1
         with:
           ruby-version: ${{ matrix.ruby }}

.github/workflows/doc.yml

@@ -10,14 +10,14 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - uses: ruby/setup-ruby@v1
         with:
           ruby-version: ruby
       - name: Generate document
         run: gem install -N yard && yard doc
       - name: Publish Documentation on GitHub Pages
-        uses: peaceiris/actions-gh-pages@v3
+        uses: peaceiris/actions-gh-pages@v4
         with:
           github_token: ${{ secrets.GITHUB_TOKEN }}
           publish_dir: ./doc