Bump pytest-doctestplus from 0.11.2 to 0.12.0 (#973)

Bumps [pytest-doctestplus](https://github.com/astropy/pytest-doctestplus) from 0.11.2 to 0.12.0.
- [Release notes](https://github.com/astropy/pytest-doctestplus/releases)
- [Changelog](https://github.com/astropy/pytest-doctestplus/blob/main/CHANGES.rst)
- [Commits](scientific-python/pytest-doctestplus@v0.11.2...v0.12.0)

---
updated-dependencies:
- dependency-name: pytest-doctestplus
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>

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

Author: dependabot[bot]

requirements_dev_optional.txt

@@ -16,7 +16,7 @@ tox==3.24.5
 coverage
 flake8==4.0.1
 pytest-cov==3.0.0
-pytest-doctestplus==0.11.2
+pytest-doctestplus==0.12.0
 pytest-timeout==2.1.0
 h5py==3.6.0
 fsspec==2022.2.0