test: fix (and simplify) changed email address generation

[jennifer-richards]

This is a better fix than #4918. The generate-and-check loop with the EmailFactory was nonsense. The loop checked whether two Email instances were the same which would never be true (aside from the initial test before the factory was called). The condition should have tested equality of Email.address, but that is the primary key for the model/table so was guaranteed to be different unless the factory had caused a primary key collision.

This just specifies a changed email address and gets rid of the loop and randomness.

[codecov]

Codecov Report

Merging #4919 (3b0de30) into main (bc1cba1) will decrease coverage by 0.00%.
The diff coverage is 83.72%.

@@            Coverage Diff             @@
##             main    #4919      +/-   ##
==========================================
- Coverage   88.47%   88.46%   -0.01%     
==========================================
  Files         296      296              
  Lines       39795    39806      +11     
==========================================
+ Hits        35208    35214       +6     
- Misses       4587     4592       +5     

Impacted Files	Coverage Δ
ietf/review/utils.py	89.57% <ø> (-0.03%)	⬇️
ietf/doc/utils.py	88.05% <77.77%> (-0.16%)	⬇️
ietf/doc/views_doc.py	91.18% <84.37%> (+0.40%)	⬆️
ietf/doc/models.py	88.16% <100.00%> (+0.01%)	⬆️
ietf/doc/templatetags/ballot_icon.py	84.82% <100.00%> (ø)
ietf/doc/views_search.py	88.81% <0.00%> (-0.83%)	⬇️
ietf/utils/draft.py	71.44% <0.00%> (-0.31%)	⬇️
ietf/nomcom/utils.py	91.30% <0.00%> (-0.25%)	⬇️
ietf/person/utils.py	86.98% <0.00%> (+0.59%)	⬆️

Help us with your feedback. Take ten seconds to tell us how you rate us. Have a feature suggestion? Share it here.