NAS-132361 / 25.04 / Fix runtest.py when an absolute path is provided to --tests

[bmeagherix]

A previous fix (#14880) did not take account of when an absolute path is provided to --tests. Rectify.

With this the following all work:

~/truenas/middleware/tests$ ./runtest.py -v --ip scale3 --interface enp0s8 --password password --test test_mock_remote.py
~/truenas/middleware/tests$ ./runtest.py -v --ip scale3 --interface enp0s8 --password password --test api2/test_mock_remote.py
~/truenas/middleware/tests$ ./runtest.py -v --ip scale3 --interface enp0s8 --password password --tests test_mock_remote.py
~/truenas/middleware/tests$ ./runtest.py -v --ip scale3 --interface enp0s8 --password password --tests api2/test_mock_remote.py
~/truenas/middleware/tests$ ./runtest.py -v --ip scale3 --interface enp0s8 --password password --tests /home/brian/truenas/middleware/tests/api2/test_mock_remote.py

[bugclerk]

Jira URL: https://ixsystems.atlassian.net/browse/NAS-132361

[yocalebo]

This makes sense but this is becoming unnecessarily complicated. I'm not asking for you to fix it in this PR (i'll probably open another PR) but we should consider using pathlib.Path module for this type of manipulation/checks.

[bugclerk]

This PR has been merged and conversations have been locked.
If you would like to discuss more about this issue please use our forums or raise a Jira ticket.