[all][gate] Bandit version 1.8.1 issues

Hi Stackers, I was re-checking some simple Neutron changes and noticed our pep8 job started failing running bandit. Seems there was a new version (1.8.1) just released and it's generating false-positives [0]. I filed a bug against it at [1], and for now I'll just work around it by ignoring B106 warnings in Neutron with [2]. Didn't know if we wanted to pin/denylist it while the issue is addressed as I'm assuming others projects will start seeing the same failure. -Brian [0] https://bugs.launchpad.net/neutron/+bug/2093849 [1] https://github.com/PyCQA/bandit/issues/1216 [2] https://review.opendev.org/c/openstack/neutron/+/939004