[dep] #188: Minimal pytest v6.2.5 for Py3.10 support

https://docs.pytest.org/en/6.2.x/changelog.html#pytest-6-2-5-2021-08-29

pyproject.toml

@@ -38,7 +38,7 @@ pyaes = "^1.6.1"
 mnemonic = "^0.19"
 
 [tool.poetry.dev-dependencies]
-pytest = "^6.2.3"
+pytest = "^6.2.5"
 pytest-cov = "^2.12.0"
 pytest-sugar = "^0.9.4"
 black = {version = "^21.4b2", allow-prereleases = true}