Remove noise in CI tests

[Hypnosphi]

Issue: CI unit tests on release/3.3 have a lot of Failed to collect coverage noise. This PR removes it by ignoring CLI snapshots and fixtures

[Hypnosphi]

For some reason, those 2 files kept producing noise even after adding an ignore pattern

[codecov]

Codecov Report

Merging #2288 into release/3.3 will increase coverage by 0.86%.
The diff coverage is n/a.

@@               Coverage Diff               @@
##           release/3.3    #2288      +/-   ##
===============================================
+ Coverage        22.61%   23.47%   +0.86%     
===============================================
  Files              346      311      -35     
  Lines             6787     6538     -249     
  Branches           896      814      -82     
===============================================
  Hits              1535     1535              
+ Misses            4564     4404     -160     
+ Partials           688      599      -89

Impacted Files	Coverage Δ
app/react/src/server/utils.js	0% <0%> (-53.58%)	⬇️
lib/ui/src/modules/ui/routes.js	0% <0%> (ø)	⬆️
addons/knobs/src/components/types/Boolean.js	11.62% <0%> (ø)	⬆️
...es__/update-addon-info/update-addon-info.output.js	0% <0%> (ø)	⬆️
...res__/update-addon-info/update-addon-info.input.js	0% <0%> (ø)	⬆️
app/react/src/client/preview/element_check.js	41.17% <0%> (ø)	⬆️
addons/storyshots/src/require_context.js	45.58% <0%> (ø)	⬆️
.../ui/src/modules/ui/components/layout/dimensions.js	15.62% <0%> (ø)	⬆️
addons/info/src/components/types/InstanceOf.js	16.66% <0%> (ø)	⬆️
addons/actions/src/util.js	18.91% <0%> (ø)	⬆️
... and 68 more

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