Fix tox4 errors

- Remove skipsdist that it was never supported and causes breakage
when used with usedevelop.
- add script to allowlist

Change-Id: Ib823caf3d90b02d5a280aa9f7ae1c25edafd9f0b

Author: elfosardo

tox.ini

@@ -1,6 +1,5 @@
 [tox]
 minversion = 3.18.0
-skipsdist = True
 envlist = py3,pep8
 ignore_basepython_conflict=true
 
@@ -36,6 +35,7 @@ deps =
     pycodestyle>=2.0.0,<3.0.0 # MIT
     doc8>=0.6.0 # Apache-2.0
 allowlist_externals = bash
+                      {toxinidir}/tools/run_bashate.sh
 commands =
   bash tools/flake8wrap.sh {posargs}
   # Run bashate during pep8 runs to ensure violations are caught by