Correct paths of existing regression tests in unit test docstrings

[timothy-nunn]

See the issue description for the references I can't correct (the files no longer, or never did, exist as regression tests).

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 48.64%. Comparing base (84679f5) to head (a806b0e).

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #4426   +/-   ##
=======================================
  Coverage   48.64%   48.64%           
=======================================
  Files         151      151           
  Lines       29703    29703           
=======================================
  Hits        14449    14449           
  Misses      15254    15254           

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[clmould]

Have discussed and will update the remaining files where possible to explain them (eg the pumping_2 is LT with different pumping model). Where this isn't possible, it will be made clear the file no longer exists in the PROCESS repo (but are available within the group)

[clmould]

• test_pfcoil has 3 instances of 'baseline2019/baseline 2019', can these be fixed please

• Could the updated refs have their line lengths fixed too please as they are quite long, -I think running the improve-quality-job should pick these up

• Can these references also be tidied up please:
  

[clmould]

A few small things

Could you fix the 'line too long' errors when running hatch run lint:fmt_extra tests/ please

[clmould]

Could you fix the 'Line too long' errors in 'improve_quality_check' please