Minor tox fixes (#1761)

- newer name for externals
- avoid using custom callbacks (will break with newer ansible
  versions)

tox.ini

@@ -65,7 +65,7 @@ setenv =
   PIP_DISABLE_PIP_VERSION_CHECK = 1
   PRE_COMMIT_COLOR = always
   FORCE_COLOR = 1
-whitelist_externals =
+allowlist_externals =
   sh
 
 [testenv:lint]
@@ -155,7 +155,6 @@ setenv =
   ANSIBLE_FORCE_COLOR=1
   ANSIBLE_NOCOWS=1
   ANSIBLE_PYTHON_INTERPRETER=auto_silent
-  ANSIBLE_STDOUT_CALLBACK=yaml
   NO_COLOR=1
 
 [testenv:packaging]