Revert "Fix TestEnv for subpackages: precompile only the new test Project"

[NHDaly]

Reverts #90

Apparently this introduced a bug relating to test dependencies that require Pkg.build().
We will revert the previous PR and make a new release, then try the PR again.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 78.17%. Comparing base (80e3754) to head (fe5ca9d).
⚠️ Report is 3 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #113      +/-   ##
==========================================
- Coverage   78.27%   78.17%   -0.10%     
==========================================
  Files          34       34              
  Lines         925      921       -4     
==========================================
- Hits          724      720       -4     
  Misses        201      201              

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[oxinabox]

thank you