Remove some tests of internal API

[MichaelChirico]

Closes #1692.

[codecov]

Codecov Report

Attention: Patch coverage is 0% with 2 lines in your changes missing coverage. Please review.

Project coverage is 99.26%. Comparing base (ae4046e) to head (0d90880).
Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
R/make_linter_from_regex.R	0.00%	2 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2801      +/-   ##
==========================================
- Coverage   99.64%   99.26%   -0.39%     
==========================================
  Files         127      127              
  Lines        7094     7094              
==========================================
- Hits         7069     7042      -27     
- Misses         25       52      +27     

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