ci fix: 빌드 오류 해결을 위해 jekyll 최신버전으로 변경

ruby/setup-ruby#595 (comment)

Author: KIM JEONG HO

.github/workflows/jekyll.yml

@@ -34,7 +34,7 @@ jobs:
       - name: Checkout
         uses: actions/checkout@v4
       - name: Setup Ruby
-        uses: ruby/setup-ruby@8575951200e472d5f2d95c625da0c7bec8217c42 # v1.161.0
+        uses: ruby/setup-ruby@v1
         with:
           ruby-version: '3.1' # Not needed with a .ruby-version file
           bundler-cache: true # runs 'bundle install' and caches installed gems automatically