ci: save page since last pushed commit

.github/workflows/jekyll.yml

@@ -73,7 +73,7 @@ jobs:
     name: Save posts to Wayback Machine
     runs-on: ubuntu-latest
     needs: deploy
-    if: github.event_name	!= 'workflow_dispatch'
+    if: github.event_name != 'workflow_dispatch'
     steps:
       # setup python
       - name: Set up Python
@@ -88,19 +88,17 @@ jobs:
       # find all modified files under `_posts` folder
       - name: Checkout
         uses: actions/checkout@v4
-        with:
-          fetch-depth: 5
       - name: Find modified posts
         id: changed-posts
         uses: tj-actions/changed-files@v42
         with:
           json: true
           files: |
             _posts/*.md
-          fetch_depth: 5
           quotepath: false
           safe_output: false
           escape_json: false
+          since_last_remote_commit: true
       # use all_changed_files
       - name: Save Page
         if: steps.changed-posts.outputs.all_changed_files != '[]' && steps.changed-posts.outputs.all_changed_files != ''