stx/platform-armada-app uses soon-to-be deprecated pip install --use-deprecated legacy-resolver

[Ghada Khalil]

Brief Description
-----------------
Opened on behalf of <email address hidden>

The pip team is planning to depreciate the '--use-deprecated legacy-resolver'
install option. While a firm date has yet to be set, We need to be ready for
the change.

Our usage seems to be confined to 'tox.ini' files. When the upstream pip change
change is delivered, we can expect.
- Build failures due to failed unit tests
- Zuul to vote -q on code reviews in some repos

This LP tracks addressing the issue with the following files:
cgcs-root/stx/platform-armada-app/python-k8sapp-platform/k8sapp_platform/tox.ini

Severity
--------
Major:

Steps to Reproduce
------------------
Scan source code with ....
grep -r 'use-deprecated' $MY_REPO

Expected Behavior
------------------
Not found

Actual Behavior
----------------
Found 8 files using the offending option

Reproducibility
---------------
100%

System Configuration
--------------------
N/A

Branch/Pull Time/Commit
-----------------------
March 9, 2022

Last Pass
---------
N/A

Timestamp/Logs
--------------
N/A

Test Activity
-------------
Build

Workaround
----------
N/A

[Ghada Khalil (gkhalil)]

Screening: stx.8.0 / there is no hard deadline for this. Doesn't appear that any other open-infra projects are actively addressing these issues either. Park until after stx.7.0 and target for stx.8.0

[Ghada Khalil (gkhalil)]

Screening: Still no deadline as per confirmation from Scott, so this doesn't affect the release of stx.8.0