Update tox.ini to work with tox 4

This change will allow this repo to pass zuul now
that this has merged:
https://review.opendev.org/c/zuul/zuul-jobs/+/866943

Tox 4 deprecated whitelist_externals.
Replace whitelist_externals with allowlist_externals

Partial-Bug: #2000399

Signed-off-by: Al Bailey <al.bailey@windriver.com>
Change-Id: I947f803712bd0dd482f9c35ba0a959f053584577

modules/tox.ini

@@ -20,7 +20,7 @@ recreate = True
 # Note: centos developer env requires ruby-devel
 # Ubuntu developer env requires ruby-dev
 deps =
-whitelist_externals =
+allowlist_externals =
     gem
     bash
 setenv =

puppet-manifests/tox.ini

@@ -20,7 +20,7 @@ recreate = True
 # Note: centos developer env requires ruby-devel
 # Ubuntu developer env requires ruby-dev
 deps =
-whitelist_externals =
+allowlist_externals =
     gem
     bash
 setenv =

tox.ini

@@ -15,7 +15,7 @@ setenv =
 deps =
   -r{toxinidir}/requirements.txt
   -r{toxinidir}/test-requirements.txt
-whitelist_externals =
+allowlist_externals =
   bash
 
 [testenv:shellcheck]
@@ -116,7 +116,7 @@ commands = bindep test
 basepython = python3
 # Note: centos developer env requires ruby-devel
 # Ubuntu developer env requires ruby-dev
-whitelist_externals =
+allowlist_externals =
     gem
     bash
 setenv =