This change will allow this repo to pass zuul now
that this has merged:
Tox 4 deprecated whitelist_externals.
Replace whitelist_externals with allowlist_externals
skipsdist and usedevelop are incompatible in tox 4.
Setting tox < 4 in .zuul.yaml rather than trying to
figure out why the sysinv component is not properly
installing in tox.
Signed-off-by: Al Bailey <firstname.lastname@example.org>