Bump pytest-doctestplus from 1.2.0 to 1.2.1 (zarr-developers#1699)

Bumps [pytest-doctestplus](https://github.com/scientific-python/pytest-doctestplus) from 1.2.0 to 1.2.1.
- [Release notes](https://github.com/scientific-python/pytest-doctestplus/releases)
- [Changelog](https://github.com/scientific-python/pytest-doctestplus/blob/main/CHANGES.rst)
- [Commits](scientific-python/pytest-doctestplus@v1.2.0...v1.2.1)

---
updated-dependencies:
- dependency-name: pytest-doctestplus
  dependency-type: direct:development
  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>
Co-authored-by: Sanket Verma <[email protected]>

Author: dependabot[bot]

requirements_dev_optional.txt

@@ -15,7 +15,7 @@ pymongo==4.6.2
 # optional test requirements
 coverage
 pytest-cov==4.1.0
-pytest-doctestplus==1.2.0
+pytest-doctestplus==1.2.1
 pytest-timeout==2.3.1
 h5py==3.10.0
 fsspec==2023.12.2