Update jekyll.yml

- update `actions/checkout` to `v4` and add `fetch-depth`
- this fixes #46

.github/workflows/jekyll.yml

@@ -32,7 +32,9 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
       - name: Setup Ruby
         uses: ruby/setup-ruby@55283cc23133118229fd3f97f9336ee23a179fcf # v1.146.0
         with: