Fix issues with tox 4.2.4

tox now hard fails if there is mismatch in spec
attributes[1]. This works around the issue
temporarily. We probably have to drop py38 jobs
and specify basepython for py39 target in the
future.

Removes ansible-galaxy --timeout for py* jobs to
workaround. We may hit the timeout with py* jobs.

[1] https://github.com/tox-dev/tox/pull/2824/

Change-Id: Ie9bacf18cf167139601eff80bba91f2b3454b5dd

tox.ini

@@ -1,7 +1,7 @@
 [tox]
 minversion = 2.0
-skipsdist = True
 envlist = pep8,py
+ignore_base_python_conflict = True
 
 [testenv]
 basepython = python3
@@ -12,6 +12,9 @@ deps =
     -r{toxinidir}/requirements.txt
     -r{toxinidir}/test-requirements.txt
 commands = stestr run --slowest {posargs}
+allowlist_externals =
+  bash
+  ./run-flake8
 
 [testenv:venv]
 commands = {posargs}