[RHELC-1295] Change OVERRIDABLE result to WARNING message in package update action

[pr-watson]

This PR changes an OVERRDIABLE result to a WARNING message in actions/package_updates.py for the case when a failure occurs in checking whether the installed packages on a system are up to date. This is to prevent the previous behavior of inhibiting the conversion when the mentioned check fails.

Jira Issues: RHELC-1295

Checklist

• PR has been tested manually in a VM (either author or reviewer)
• Jira issue has been made public if possible
• [RHELC-] is part of the PR title
• GitHub label has been added to help with Release notes
• PR title explains the change from the user's point of view
• Code and tests are documented properly
• The commits are squashed to as few commits as possible (without losing data)
• When merged: Jira issue has been updated to Release Pending if relevant

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Comparison is base (96470e9) 94.35% compared to head (a3844d3) 94.34%.
Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1026      +/-   ##
==========================================
- Coverage   94.35%   94.34%   -0.01%     
==========================================
  Files          47       47              
  Lines        4588     4580       -8     
  Branches      819      818       -1     
==========================================
- Hits         4329     4321       -8     
  Misses        182      182              
  Partials       77       77              

Flag	Coverage Δ
centos-linux-7	89.55% <ø> (-0.02%)	⬇️
centos-linux-8	90.54% <ø> (-0.02%)	⬇️
centos-linux-9	90.60% <ø> (-0.02%)	⬇️

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[has-bot]

/packit test --labels sanity

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@oamg/conversions-qe please review results and provide ack.

Log | Bot Usage

[Venefilyn]

Needs a rebase

[bocekm]

This PR impacts the https://github.com/oamg/convert2rhel/wiki/Environment-variables. I'll update it now by removing the CONVERT2RHEL_PACKAGE_UP_TO_DATE_CHECK_SKIP from there. Please don't forget to update the wiki with future changes to environment variables.