Fix pep8 and doc jobs for tox4

Add bash to allowlist_externals

Change-Id: Idb063586fa6e6e0d9c4ecc61fc661338f6759e08

tox.ini

@@ -1,7 +1,6 @@
 [tox]
-envlist = py39,py38,pep8
+envlist = py39,py38,pep8,docs
 minversion = 3.18.0
-skipsdist = True
 
 [testenv]
 setenv = VIRTUAL_ENV={envdir}
@@ -13,7 +12,7 @@ usedevelop = True
 deps = -c{env:TOX_CONSTRAINTS_FILE:https://opendev.org/openstack/requirements/raw/branch/master/upper-constraints.txt}
        -r{toxinidir}/requirements.txt
        -r{toxinidir}/test-requirements.txt
-allowlist_externals = sh
+allowlist_externals = bash
 commands =
   stestr run {posargs}
 # there is also secret magic in stestr which lets you run in a fail only
@@ -30,7 +29,7 @@ setenv =
   OS_ROOTWRAP_DAEMON_CMD=sudo {envdir}/bin/neutron-rootwrap-daemon {envdir}/etc/neutron/rootwrap.conf
   OS_FAIL_ON_MISSING_DEPS=1
 allowlist_externals =
-  sh
+  bash
   cp
   sudo
 
@@ -53,7 +52,7 @@ setenv =
 deps = {[testenv:functional]deps}
 allowlist_externals = {[testenv:functional]allowlist_externals}
 commands =
-  {toxinidir}/tools/deploy_rootwrap.sh {toxinidir} {envdir}
+  bash {toxinidir}/tools/deploy_rootwrap.sh {toxinidir} {envdir}
   stestr run {posargs}
 
 [testenv:dsvm-functional-sswan]
@@ -81,11 +80,12 @@ deps =
 commands =
   flake8
   pylint --rcfile=.pylintrc --output-format=colorized {posargs:neutron_vpnaas}
-  {toxinidir}/tools/check_unit_test_structure.sh
+  bash {toxinidir}/tools/check_unit_test_structure.sh
   neutron-db-manage --subproject neutron-vpnaas --database-connection sqlite:// check_migration
   {[testenv:genconfig]commands}
   {[testenv:genpolicy]commands}
-allowlist_externals = sh
+allowlist_externals =
+  bash
 
 [testenv:pep8-dev]
 deps =
@@ -151,7 +151,7 @@ import_exceptions = neutron_vpnaas._i18n
 local-check-factory = neutron_lib.hacking.checks.factory
 
 [testenv:genconfig]
-commands = {toxinidir}/tools/generate_config_file_samples.sh
+commands = bash {toxinidir}/tools/generate_config_file_samples.sh
 
 [testenv:genpolicy]
 commands = oslopolicy-sample-generator --config-file=etc/oslo-policy-generator/policy.conf