test: improve zlib tests

[anonrig]

Remove several unnecessary zlib tests, and use node:test as much as we can. This also avoids calling require('../common') functionality as much as we can.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 88.38%. Comparing base (5d4fee8) to head (e337280).
Report is 66 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #55716      +/-   ##
==========================================
- Coverage   88.42%   88.38%   -0.04%     
==========================================
  Files         654      654              
  Lines      187662   187575      -87     
  Branches    36118    36087      -31     
==========================================
- Hits       165945   165796     -149     
- Misses      14955    15019      +64     
+ Partials     6762     6760       -2     

see 77 files with indirect coverage changes

[lpinca]

I'm fine with removing redundant tests but I'm -1 on using node:test as much as we can as per #54796 and #55110 (review). In my opinion this is not an improvement, but added complexity and spurious code executed as part of the test, which could also affect the reliability of the test itself.