Bump rossjrw/pr-preview-action from 1.4.8 to 1.6.0 (#24)

Author: ytdHuang

.github/workflows/preview.yml

@@ -38,7 +38,7 @@ jobs:
         with:
           to: html
       - name: Deploy PR Preview
-        uses: rossjrw/pr-preview-action@v1.4.8
+        uses: rossjrw/pr-preview-action@v1.6.0
         with:
           source-dir: ./_output/
         env: