maint(gui-ubuntupro): Remove generated mock files

[ashuntu]

Removes all generated *.mocks.dart files from the ubuntupro apps. These were removed since they aren't necessarily stable and can be generated locally and in CI anyway by running dart run build_runner build. This also means that developers no longer have to make sure to regenerate mocks when modifying the tests or models.

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UDENG-5592

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 89.11%. Comparing base (aea00b5) to head (94d37ea).
Report is 7 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1018      +/-   ##
==========================================
+ Coverage   89.10%   89.11%   +0.01%     
==========================================
  Files         112      112              
  Lines        7498     7498              
==========================================
+ Hits         6681     6682       +1     
+ Misses        639      638       -1     
  Partials      178      178              

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[CarlosNihelton]

Glad to align the practices of the Apps team.