Bump plotly from 5.5.0 to 5.6.0 (#899)

Bumps [plotly](https://github.com/plotly/plotly.py) from 5.5.0 to 5.6.0.
- [Release notes](https://github.com/plotly/plotly.py/releases)
- [Changelog](https://github.com/plotly/plotly.py/blob/master/CHANGELOG.md)
- [Commits](plotly/plotly.py@v5.5.0...v5.6.0)

---
updated-dependencies:
- dependency-name: plotly
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

requirements_docs.txt

@@ -7,7 +7,7 @@ jupyterlab>=3.2.8
 matplotlib==3.5.1
 numpydoc==1.2
 pandas==1.4.1
-plotly==5.5.0
+plotly==5.6.0
 pyansys_sphinx_theme==0.2.1
 pypandoc==1.7.2
 pytest-sphinx==0.3.1