fix(eslint-plugin): [no-unnec-type-arg] undefined symbol crash

[quentin-jaquier-sonarsource]

Fixes #1006

[typescript-eslint]

Thanks for the PR, @quentin-jaquier-sonarsource!

typescript-eslint is a 100% community driven project, and we are incredibly grateful that you are contributing to that community.

The core maintainers work on this in their personal time, so please understand that it may not be possible for them to review your work immediately.

Thanks again!

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[codecov]

Codecov Report

Merging #1007 into master will increase coverage by <.01%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##           master    #1007      +/-   ##
==========================================
+ Coverage   94.13%   94.14%   +<.01%     
==========================================
  Files         115      115              
  Lines        5016     5019       +3     
  Branches     1403     1404       +1     
==========================================
+ Hits         4722     4725       +3     
  Misses        166      166              
  Partials      128      128

Impacted Files	Coverage Δ
...-plugin/src/rules/no-unnecessary-type-arguments.ts	91.66% <100%> (+0.55%)	⬆️

[bradzacher]

LGTM - thanks for fixing this

[quentin-jaquier-sonarsource]

Thanks for your quick reaction.

Funny story, I realized that this issue was in fact reported by... the plugin itself (rule no-non-null-assertion)!
Too bad we did not manage to eat our own dog food to prevent this bug!
Still, it's nice to see that this rule is reporting relevant true positive 👍