Fix isort failures in utilities

[arnaudgelas]

What does this PR do?

Relates to #4805

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[codecov]

Codecov Report

Merging #5530 (84b585b) into release/1.2-dev (8629048) will not change coverage.
The diff coverage is 100%.

@@               Coverage Diff               @@
##           release/1.2-dev   #5530   +/-   ##
===============================================
  Coverage               93%     93%           
===============================================
  Files                  152     152           
  Lines                10736   10736           
===============================================
  Hits                  9948    9948           
  Misses                 788     788           

[rohitgr7]

docs checks are failing.. can you check?
https://github.com/PyTorchLightning/pytorch-lightning/pull/5530/checks?check_run_id=1709162903

.

[Borda]

docs checks are failing.. can you check?
https://github.com/PyTorchLightning/pytorch-lightning/pull/5530/checks?check_run_id=1709162903

it seems to be unrelated as the template is missing and we have not touched it here...

  File "/github/workspace/docs/source/conf.py", line 22, in <module>
    import pt_lightning_sphinx_theme
ModuleNotFoundError: No module named 'pt_lightning_sphinx_theme'