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: I9d181840a5471386675d0fe0bd134da8bda5b2cb

.zuul.yaml

@@ -30,7 +30,7 @@
     vars:
         tox_envlist: py39
         python_version: 3.9
-        tox_extra_args: python-k8sapp-snmp/k8sapp_snmp/tox.ini
+        tox_extra_args: -c python-k8sapp-snmp/k8sapp_snmp/tox.ini
 - job:
     name: stx-snmp-armada-app-upload-git-mirror
     parent: upload-git-mirror

python-k8sapp-snmp/k8sapp_snmp/tox.ini

@@ -18,7 +18,7 @@ distshare={toxworkdir}/.tox/distshare
 sitepackages = False
 
 # tox is silly... these need to be separated by a newline....
-whitelist_externals = bash
+allowlist_externals = bash
                       find
 
 install_command = pip install --use-deprecated legacy-resolver \

tox.ini

@@ -15,7 +15,7 @@ setenv =
 deps =
   -r{toxinidir}/requirements.txt
   -r{toxinidir}/test-requirements.txt
-whitelist_externals =
+allowlist_externals =
   bash
 
 [testenv:bashate]