Fix testools errors

testtools v2.8.3 removed different components that stestr requires
on the current latest version deployed.
On the main branch of stestr a PR to fix this was already merged,
thus we can directly use the stestr from the main branch (to be
changed once a release is done to take into account those changes)

Updates the setuptools version to fix the following error:
No module named 'pkg_resources'

requirements.txt

@@ -1,3 +1,4 @@
+setuptools>=65.0.0,<82  # pkg_resources removed in 82; required by sqlalchemy-migrate
 eventlet
 keystoneauth1
 keystonemiddleware

test-requirements.txt

@@ -2,9 +2,9 @@
 # of appearance. Changing the order has an impact on the overall integration
 # process, which may cause wedges in the gate later.
 
+setuptools>=65.0.0,<82  # pkg_resources removed in 82; required by sqlalchemy-migrate
 hacking>=6.0.1,<=6.0.1 # Apache-2.0
 coverage!=4.4,>=4.0 # Apache-2.0
 ddt>=1.2.1 # MIT
 oslotest>=3.8.0 # Apache-2.0
-stestr>=2.0.0 # Apache-2.0
-
+stestr>=4.2.1 # Apache-2.0