[Test Gap][upgrade path][t0] Enable upgrade paths test in PR testing framework

[vaibhavhd]

Test Gap Description

Upgrade path tests are not covered in PR testing stage.

Benefit:
This test has potential to catch all non-ASIC dependent issues in upgrade path.

Why was it not done until now?
Historically these cases were not added as they have time cost to them. Previously (when Elastic TB was not a thing) these cases could have added hours to the overall runtime of a PR test.

Why can it be done now?
Now, however, we can create a new test job dedicated to upgrade path cases.

Test Plan

Cases to be added:

The case already exist. Ask in this issue is to validate the feasibility of existing test in KVM test suite and then enable these tests in PR test framework.
https://github.com/sonic-net/sonic-mgmt/blob/master/tests/upgrade_path/test_upgrade_path.py

Test environment

I want to start w/ T0 warm-reboot upgrade variant only.

If there is a need, this ask can be further augmented to include COLD reboot upgrades;

Attach files (if any)

No response

[vaibhavhd]

@davidm-arista , @andywongarista , FYI