ci: yjit for jekyll build

Author: toshimaru

Diff for: .github/workflows/ci.yml

@@ -10,6 +10,11 @@ jobs:
   jekyll-build:
     runs-on: ubuntu-latest
     name: Jekyll Build
+    strategy:
+      matrix:
+        yjit-enabled: [0, 1]
+    env:
+      RUBY_YJIT_ENABLE: ${{ matrix.yjit-enabled }}
     steps:
       - uses: actions/checkout@v4
       - uses: ruby/setup-ruby@v1