Set _DeviceDtypeModuleMixin _device from torch's default device function

[GdoongMathew]

What does this PR do?

Fixes #20307

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📚 Documentation preview 📚: https://pytorch-lightning--21164.org.readthedocs.build/en/21164/

[Borda]

since the change is with Fabric lets add slo relevant test to fabric

[bhimrazy]

Will look into the other failing tests shortly.

[GdoongMathew]

Hi @bhimrazy & @Borda , my bad, I forgot to set back the default dtype in torch in the newly added unittest. Should be fixed in c323507

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 87%. Comparing base (d204cb1) to head (0e729d6).

Additional details and impacted files

@@           Coverage Diff           @@
##           master   #21164   +/-   ##
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- Coverage      87%      87%   -0%     
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  Files         269      269           
  Lines       23656    23657    +1     
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- Hits        20636    20634    -2     
- Misses       3020     3023    +3