fix(ci): don't collect coverage for eol tests

[pichlermarc]

Which problem is this PR solving?

nyc requires istanbul-lib-report, which silently dropped support for Node.js v8 when going from
3.0.0 to 3.0.1 by requiring make-dir@^4.0.0 to fix GHSA-c2qf-rxjj-qqgw. make-dir@4.0.0 does not support Node.js v8 anymore, which causes the eol tests to fail.

As we don't report the coverage in these tests, I opted to run the tests without nyc instead of pinning the package (as pinning would mean we're stuck with that version, which may prevent us from updating in the future, even though we don't use it).

Short description of the changes

• Introduced test:eol script which runs tests, but does not run them with nyc
• adapted the github workflow to use that script instead

Type of change

• internal change (does not affect users)
• Bug fix (non-breaking change which fixes an issue)

How Has This Been Tested?

• manual testing
• running in CI

[codecov]

Codecov Report

Merging #4030 (2d30990) into main (c021b10) will not change coverage.
The diff coverage is n/a.

❗ Current head 2d30990 differs from pull request most recent head d9fdf3c. Consider uploading reports for the commit d9fdf3c to get more accurate results

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #4030   +/-   ##
=======================================
  Coverage   92.31%   92.31%           
=======================================
  Files         321      321           
  Lines        9189     9189           
  Branches     1953     1953           
=======================================
  Hits         8483     8483           
  Misses        706      706           

[pichlermarc]

/easycla

[legendecas]

Fixes #4029

[legendecas]

/easycla