Bump sphinxcontrib-spelling from 7.2.1 to 7.3.0 in /requirements

Bumps [sphinxcontrib-spelling](https://github.com/sphinx-contrib/spelling) from 7.2.1 to 7.3.0.
- [Release notes](https://github.com/sphinx-contrib/spelling/releases)
- [Commits](sphinx-contrib/spelling@7.2.1...7.3.0)

---
updated-dependencies:
- dependency-name: sphinxcontrib-spelling
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

requirements/dev-requirements.txt

@@ -29,7 +29,7 @@ requests-mock-flask==2021.7.10.0
 sphinx-autodoc-typehints==1.12.0
 sphinx_paramlinks==0.5.2
 sphinxcontrib-httpdomain==1.8.0
-sphinxcontrib-spelling==7.2.1
+sphinxcontrib-spelling==7.3.0
 twine==3.7.0
 types-Flask==1.1.6
 types-freezegun==1.1.3