CI: Pinning doc previewer action to current release

Author: datapythonista

.github/workflows/comment-commands.yml

@@ -24,7 +24,7 @@ jobs:
  concurrency:
  group: ${{ github.actor }}-preview-docs
  steps:
- - uses: pandas-dev/github-doc-previewer@master
+ - uses: pandas-dev/github-doc-previewer@v0.3.1
  with:
  previewer-server: "https://pandas.pydata.org/preview"
  artifact-job: "Doc Build and Upload"