snap refresh might cause snap config to be reset to default

[Dmitrii Shcherbakov]

This legacy chunk of code in the post-refresh hook may cause set-default-config.py to be executed causing dynamic config values to be overridden.

https://opendev.org/x/microstack/src/commit/95fec9667731b765596196217c4e8605d7156b6d/snap/hooks/post-refresh#L7-L14

Which can result in virt-type being changed from "kvm" to qemu:

        'config.nova.virt-type': 'qemu',
        'config.nova.cpu-mode': 'host-model',

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.opendev.org/c/x/microstack/+/807115

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.opendev.org/c/x/microstack/+/807115
Committed: https://opendev.org/x/microstack/commit/517649084529de5dbe270be95c71ba9bc79acfe3
Submitter: "Zuul (22348)"
Branch: master

commit 517649084529de5dbe270be95c71ba9bc79acfe3
Author: Dmitrii Shcherbakov <email address hidden>
Date: Thu Sep 2 13:54:22 2021 +0300

    Remove legacy post-refresh hook code

    The versions in question have been outdated for a long time and nowadays
    those code paths cause unnecessary overriding of calculated config
    values with the default ones.

    Closes-Bug: #1942433
    Change-Id: I1393e8c5197cdb8ea83ad2a4c41e0bc5a219c509