[MRG] Include 'part' in the entity list

[teonbrooks]

Update utils.py

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PR Description

part is missing from the entity list. It is introduced for the fif files in the appendix but it isn't being captured in our parsing step

Merge checklist

Maintainer, please confirm the following before merging:

• All comments resolved
• This is not your own PR
• All CIs are happy
• PR title starts with [MRG]
• whats_new.rst is updated
• PR description includes phrase "closes <#issue-number>"
• Commit history does not contain any merge commits

[jasmainak]

test please :-)

[codecov-io]

Codecov Report

Merging #346 into master will not change coverage.
The diff coverage is 100%.

@@           Coverage Diff           @@
##           master     #346   +/-   ##
=======================================
  Coverage   95.14%   95.14%           
=======================================
  Files          11       11           
  Lines        1277     1277           
=======================================
  Hits         1215     1215           
  Misses         62       62

Impacted Files	Coverage Δ
mne_bids/utils.py	98.3% <100%> (ø)	⬆️

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[teonbrooks]

@jasmainak it's all good to go

[jasmainak]

do you want to update whats_new.rst? otherwise, it's good to go

[jasmainak]

sorry there are merge conflicts now ...

[jasmainak]

Thanks @teonbrooks !