Remove nose from dependencies

Nose library not only deprecated but Debian now removed it, see [1], so
it is time to get rid of all referencies in our code.

[1]: https://lists.openstack.org/pipermail/openstack-discuss/2022-August/030165.html

Change-Id: Ib56d19af2e1d0240a2ac044cd857b24480f27608
diff --git a/.gitignore b/.gitignore
index a678dd2..228b0a8 100644
--- a/.gitignore
+++ b/.gitignore
@@ -26,7 +26,6 @@
 .coverage*
 !.coveragerc
 .tox
-nosetests.xml
 .venv
 .stestr/
 
diff --git a/requirements.txt b/requirements.txt
index f25caec..34531e9 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -15,7 +15,6 @@
 tempest>=29.2.0 # Apache-2.0
 tenacity>=3.2.1 # Apache-2.0
 ddt>=1.0.1 # MIT
-nose>=1.3.7 # LGPL
 testtools>=2.2.0 # MIT
 testscenarios>=0.4 # Apache-2.0/BSD
 eventlet!=0.18.3,!=0.20.1,>=0.18.2 # MIT