module: reject package map subpaths that escape the target package

[islandryu]

Fixes: #65501

[nodejs-github-bot]

Review requested:

• @nodejs/loaders

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 90.14%. Comparing base (65f518c) to head (ddd6558).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #65502      +/-   ##
==========================================
+ Coverage   90.12%   90.14%   +0.01%     
==========================================
  Files         751      751              
  Lines      252638   252653      +15     
  Branches    47551    47552       +1     
==========================================
+ Hits       227689   227747      +58     
+ Misses      16238    16196      -42     
+ Partials     8711     8710       -1     

Files with missing lines	Coverage Δ
lib/internal/modules/package_map.js	100.00% <100.00%> (ø)

... and 35 files with indirect coverage changes

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