Fix snap autorefresh

[javierdelapuente]

Applicable spec:

Overview

We are having failures in integration tests because snaps are refreshing automatically, see
https://github.com/canonical/github-runner-operator/actions/runs/12709354816/job/35506454388?pr=428

For example in the step Setup operator environment, the following error happens randomly:

Install LXD
  /usr/bin/sudo apt-get remove -qy lxd lxd-client
  Reading package lists...
  Building dependency tree...
  Reading state information...
  Package 'lxd' is not installed, so not removed
  E: Unable to locate package lxd-client
  /usr/bin/sudo snap list lxd
  Name  Version        Rev    Tracking      Publisher    Notes
  lxd   5.0.3-80aeff7  [29](https://github.com/canonical/github-runner-operator/actions/runs/12743097974/job/35512400072?pr=423#step:9:31)351  5.0/stable/…  canonical**  -
  /usr/bin/sudo snap install lxd --channel=latest/stable
  snap "lxd" is already installed, see 'snap help refresh'
  /usr/bin/sudo snap refresh lxd --channel=latest/stable
  error: snap "lxd" has "auto-refresh" change in progress
  /usr/bin/sudo snap refresh lxd --channel=latest/stable
  error: snap "lxd" has "auto-refresh" change in progress
  /usr/bin/sudo snap refresh lxd --channel=latest/stable
  error: snap "lxd" has "auto-refresh" change in progress
  /usr/bin/sudo snap refresh lxd --channel=latest/stable
  error: snap "lxd" has "auto-refresh" change in progress
  /usr/bin/sudo snap refresh lxd --channel=latest/stable
  error: snap "lxd" has "auto-refresh" change in progress
  Error: The process '/usr/bin/sudo' failed with exit code 10

Rationale

Workflow Changes

Disable autorefresh and wait for last auto refresh if there is one.

Checklist

• The contributing guide was applied
• The PR is tagged with appropriate label (urgent, trivial, complex)

[yanksyoon]

simple enough change, one comment :) thanks

[swetha1654]

LGTM