Remove trailing whitespace in a bunch of files

[fingolfin]

This happens whenever I edit those files, due to .editorconfig.
Instead of mixing it with other PRs, I thought it might be best
if I submitted this as a PR of its own.

[codecov]

Codecov Report

Attention: 11 lines in your changes are missing coverage. Please review.

Comparison is base (6d81413) 74.54% compared to head (af2d4a9) 74.62%.
Report is 2 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #1250      +/-   ##
==========================================
+ Coverage   74.54%   74.62%   +0.07%     
==========================================
  Files         346      346              
  Lines      110838   110994     +156     
==========================================
+ Hits        82627    82829     +202     
+ Misses      28211    28165      -46     

Files	Coverage Δ
src/EllCrv/Finite.jl	94.44% <ø> (-0.18%)	⬇️
src/EllCrv/FormalGroupLaw.jl	100.00% <ø> (ø)
src/EllCrv/Heights.jl	92.43% <100.00%> (ø)
src/EllCrv/MinimalModels.jl	82.88% <ø> (ø)
src/EllCrv/Misc.jl	35.50% <ø> (ø)
src/EllCrv/Models.jl	91.30% <ø> (ø)
src/EllCrv/Pairings.jl	92.63% <100.00%> (ø)
src/EllCrv/Torsion.jl	90.46% <100.00%> (ø)
src/EllCrv/Isogeny.jl	90.68% <50.00%> (ø)
src/EllCrv/Isomorphisms.jl	90.85% <0.00%> (ø)
... and 4 more

... and 21 files with indirect coverage changes

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.