chore(deps): bump pyvista from 0.46.3 to 0.46.4 in /requirements (#663)

Bumps [pyvista](https://github.com/pyvista/pyvista) from 0.46.3 to 0.46.4.
- [Release notes](https://github.com/pyvista/pyvista/releases)
- [Commits](pyvista/pyvista@v0.46.3...v0.46.4)

---
updated-dependencies:
- dependency-name: pyvista
  dependency-version: 0.46.4
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

Author: dependabot[bot]

requirements/requirements_doc.txt

@@ -6,4 +6,4 @@ sphinx_design==0.6.1
 sphinxcontrib-mermaid>=0.7.1
 sphinx-gallery==0.19.0
 Pillow>=9.0
-pyvista==0.46.3
+pyvista==0.46.4