[openstack-helm] Change whitelist_externals to allowlist_externals

Replace whitelist_externals with allowlist_externals in tox.ini

Change-Id: I0c90b92153b2781056f1590697edcc9b00a4bc0a

tox.ini

@@ -8,7 +8,7 @@ ignore_basepython_conflict = True
 basepython = python3
 setenv = VIRTUAL_ENV={envdir}
 deps = -c{env:TOX_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/master}
-passenv = *_proxy *_PROXY
+passenv = *_proxy,*_PROXY
 
 [testenv:venv]
 commands = {posargs}
@@ -20,7 +20,7 @@ deps =
 commands =
   rm -rf doc/build
   docstheme-build-translated.sh
-whitelist_externals =
+allowlist_externals =
   rm
 
 [testenv:lint]
@@ -33,7 +33,7 @@ commands =
       git clone https://opendev.org/openstack/openstack-helm-infra ../openstack-helm-infra; \
   fi'
   bash ../openstack-helm-infra/tools/gate/lint.sh
-whitelist_externals =
+allowlist_externals =
   rm
   bash