Update for tox v4 (#199)

Author: sirosen

tox.ini

@@ -45,7 +45,7 @@ commands = mypy src/ {posargs}
 [testenv:docs]
 basepython = python3.10
 extras = docs
-whitelist_externals = rm
+allowlist_externals = rm
 changedir = docs/
 # clean the build dir before rebuilding
 commands_pre = rm -rf _build/
@@ -55,7 +55,7 @@ commands = sphinx-build -d _build/doctrees -b dirhtml -W . _build/dirhtml {posar
 skip_install = true
 deps = twine
        build
-whitelist_externals = rm
+allowlist_externals = rm
 commands_pre = rm -rf dist/
 # check that twine validating package data works
 commands = python -m build
@@ -73,7 +73,7 @@ skip_install = true
 deps = twine
        build
 # clean the build dir before rebuilding
-whitelist_externals = rm
+allowlist_externals = rm
 commands_pre = rm -rf dist/
 commands = python -m build
            twine upload dist/*