Upgrade electron 26->27 to fix screen blanking

[cmdcolin]

• Removes ts-expect-error from electron.ts menu generation
• Downgrades electron 26 to 25, following some reports of issues with 26 Jbrowse 2.7.0 crash #3979

[codecov]

Codecov Report

Merging #3980 (deffcdc) into main (4ab29d5) will decrease coverage by 0.02%.
The diff coverage is 66.66%.

@@            Coverage Diff             @@
##             main    #3980      +/-   ##
==========================================
- Coverage   63.78%   63.77%   -0.02%     
==========================================
  Files        1020     1020              
  Lines       30134    30134              
  Branches     7194     7194              
==========================================
- Hits        19222    19217       -5     
- Misses      10745    10752       +7     
+ Partials      167      165       -2     

Files	Coverage Δ
...erarchicalTrackSelectorWidget/generateHierarchy.ts	80.43% <100.00%> (ø)
...ement/src/HierarchicalTrackSelectorWidget/model.ts	57.14% <0.00%> (ø)

... and 4 files with indirect coverage changes

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[cmdcolin]

changed title to reflect that it was actually upgraded