python2-* packages are not uninstalled from overcloud nodes

Bug based on https://bugzilla.redhat.com/show_bug.cgi?id=1876046

Current upgrade documentation mentions that we should uninstall python2-* packages from undercloud nodes[1].

[1] https://access.redhat.com/documentation/en-us/red_hat_openstack_platform/16.1/html-single/framework_for_upgrades_13_to_16.1/index#removing-unnecessary-packages-from-the-undercloud-ceph-4

However it doesn't mention the same for overcloud nodes so python2-* packages, and actually there are some python2-* packages left after upgrades.
If these packages are not used in overcloud nodes, we should uninstall them from overcloud nodes as well.

~~~
[heat-admin@controller-0 ~]$ rpm -qa | grep python2-* | sort
python2-2.7.17-1.module+el8.2.0+4561+f4e0d66a.x86_64
python2-asn1crypto-0.23.0-3.el7ost.noarch
python2-babel-2.5.1-9.module+el8.1.0+3111+de3f2d8e.noarch
python2-backports-1.0-15.module+el8.1.0+3111+de3f2d8e.x86_64
python2-backports-ssl_match_hostname-3.5.0.1-11.module+el8.1.0+3111+de3f2d8e.noarch
python2-chardet-3.0.4-10.module+el8.1.0+3111+de3f2d8e.noarch
python2-dateutil-2.6.1-1.el7ost.noarch
python2-idna-2.5-7.module+el8.1.0+3111+de3f2d8e.noarch
python2-ipaddress-1.0.18-6.module+el8.1.0+3111+de3f2d8e.noarch
python2-jinja2-2.10-8.module+el8.1.0+3111+de3f2d8e.noarch
python2-leapp-0.10.0-2.el7_8.noarch
python2-libs-2.7.17-1.module+el8.2.0+4561+f4e0d66a.x86_64
python2-markupsafe-0.23-19.module+el8.1.0+3111+de3f2d8e.x86_64
python2-nose-1.3.7-30.module+el8.1.0+3111+de3f2d8e.noarch
python2-pip-9.0.3-16.module+el8.2.0+5478+b505947e.noarch
python2-pip-wheel-9.0.3-16.module+el8.2.0+5478+b505947e.noarch
python2-psycopg2-2.7.5-7.module+el8.1.0+3111+de3f2d8e.x86_64
python2-pytz-2017.2-12.module+el8.1.0+3111+de3f2d8e.noarch
python2-pyyaml-3.12-16.module+el8.1.0+3111+de3f2d8e.x86_64
python2-requests-2.20.0-3.module+el8.2.0+4577+feefd9b8.noarch
python2-setuptools-39.0.1-11.module+el8.1.0+3446+c3d52da3.noarch
python2-setuptools-wheel-39.0.1-11.module+el8.1.0+3446+c3d52da3.noarch
python2-six-1.11.0-5.module+el8.1.0+3111+de3f2d8e.noarch
python2-urllib3-1.24.2-1.module+el8.1.0+3280+19512f10.noarch
~~~