fix formatting typo in seed_everything docs

[WrRan]

What does this PR do?

update pytorch_lightning/utilities/seed.py#37 ```workers=True->workers=True``

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[codecov]

Codecov Report

Merging #8052 (4c26679) into master (c7eaf76) will decrease coverage by 5%.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master   #8052    +/-   ##
=======================================
- Coverage      92%     87%    -5%     
=======================================
  Files         210     210            
  Lines       13579   13579            
=======================================
- Hits        12452   11810   -642     
- Misses       1127    1769   +642     

[awaelchli]

this ticks!