requirements: Consume nose from Git for Python 3.10

The distributed version of nose is not Python 3.10 compatible,
ref: nose-devs/nose#1118.

requirements.txt

@@ -11,7 +11,10 @@ flake8-per-file-ignores
 pydocstyle<4.0.0
 coverage
 mock>=1.2
-nose>=1.3.7
+# For some reason the PyPi distributed wheel of nose differ from the one on
+# GitHub, and it does not work with Python 3.10.
+nose>=1.3.7;python_version<'3.10'
+git+https://github.com/nose-devs/nose.git#egg=nose;python_version=='3.10'
 pbr==5.6.0
 simplejson>=2.2.0
 netifaces>=0.10.4