Update Ruby version to 3.4 in deploy workflow

Bumps the Ruby version from 3.3 to 3.4 in the GitHub Actions deploy workflow to ensure compatibility with the latest Ruby features and security updates.

Author: toshimaru

.github/workflows/deploy.yml

@@ -17,7 +17,7 @@ jobs:
       - name: Set up Ruby
         uses: ruby/setup-ruby@v1
         with:
-          ruby-version: 3.3
+          ruby-version: 3.4
           bundler-cache: true
       - name: Setup Pages
         uses: actions/configure-pages@v5