build(deps-dev): bump pytest-asyncio from 0.18.3 to 0.21.0 (#26)

Author: dependabot[bot]

poetry.lock

@@ -23,7 +23,7 @@ shed = ">=0.9.5,<2023.4.0"
 pylint = "^2.13.7"
 mypy = "^0.942"
 pytest = "^7.1.1"
-pytest-asyncio = "^0.18.3"
+pytest-asyncio = ">=0.18.3,<0.22.0"
 pytest-cov = ">=3,<5"
 typeguard = "^2.13.3"
 docformatter = "^1.4"