build(deps): bump rossjrw/pr-preview-action from 1.4.8 to 1.6.0

Bumps [rossjrw/pr-preview-action](https://github.com/rossjrw/pr-preview-action) from 1.4.8 to 1.6.0.
- [Release notes](https://github.com/rossjrw/pr-preview-action/releases)
- [Commits](rossjrw/pr-preview-action@v1.4.8...v1.6.0)

---
updated-dependencies:
- dependency-name: rossjrw/pr-preview-action
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

.github/workflows/docs_preview.yml

@@ -31,7 +31,7 @@ jobs:
           pip install -e .[dev,docs]
           make -C docs html
       - name: Deploy Preview
-        uses: rossjrw/pr-preview-action@v1.4.8
+        uses: rossjrw/pr-preview-action@v1.6.0
         with:
           source-dir: docs/_build/html
           preview-branch: gh-pages