Update pytest-asyncio requirement from ~0.21 to ~0.23 (#93)

Updates the requirements on [pytest-asyncio](https://github.com/pytest-dev/pytest-asyncio) to permit the latest version.
- [Release notes](https://github.com/pytest-dev/pytest-asyncio/releases)
- [Commits](pytest-dev/pytest-asyncio@v0.21.0...v0.23.1)

---
updated-dependencies:
- dependency-name: pytest-asyncio
  dependency-type: direct:development
...

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

Author: dependabot[bot]

pyproject.toml

@@ -30,7 +30,7 @@ pymitter = ">=0.4,<0.6"
 
 [tool.poetry.dev-dependencies]
 pytest = "~7.4"
-pytest-asyncio = "~0.21"
+pytest-asyncio = "~0.23"
 pytest-cov = "~4.1"
 pytest-unordered = "~0.5"
 pre-commit = "~3.5"