Refactor tests for TPU Accelerator

[kaushikb11]

What does this PR do?

A couple of things happening here:

• Renaming of tests/accelerator/test_tpu_backend.py to tests/accelerator/test_tpu.py
• Fixes the TPU test not being run for [1/4] Add get_device_stats to accelerator interface #9586

Does your PR introduce any breaking changes? If yes, please list them.

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[github-actions]

Build Error! No Linked Issue found. Please link an issue or mention it in the body using #<issue_id>

[rohitgr7]

did you do git mv here?

[kaushikb11]

did you do git mv here?

Nope.

[codecov]

Codecov Report

Merging #9718 (938afdf) into master (a002f87) will decrease coverage by 0%.
The diff coverage is n/a.

@@          Coverage Diff           @@
##           master   #9718   +/-   ##
======================================
- Coverage      93%     93%   -0%     
======================================
  Files         179     179           
  Lines       15803   15805    +2     
======================================
+ Hits        14647   14648    +1     
- Misses       1156    1157    +1     

[daniellepintz]

Thanks for this cleanup @kaushikb11! Looks great, however I see the TPU tests are failing with Exited with code exit status 1 (seems unrelated to any test failure?)

[kaushikb11]

however I see the TPU tests are failing with Exited with code exit status 1 (seems unrelated to any test failure?)

It's very bizarre. Started to look into it!

[daniellepintz]

Any luck @kaushikb11? Did you try rerunning the test 😅? I'd like to merge this soon if possible so I can rebase #9712 on top

[tchaton]

LGTM !

[daniellepintz]

@kaushikb11 I see you still have the TPU test failure Exited with code exit status 1 :/
https://app.circleci.com/pipelines/github/PyTorchLightning/pytorch-lightning/44976/workflows/4ed86e1b-7da9-4280-b3ee-a559023b276a/jobs/132914/parallel-runs/0/steps/0-119

You believe this is due to test_device_stats_tpu, correct? Would it make sense to delete the test if that is the case, since the logic is mostly tested in

https://github.com/PyTorchLightning/pytorch-lightning/blob/6feda08109cdf96173627b2599613e62b3d012dd/tests/callbacks/test_device_stats_monitor.py#L86