sea: add test and update docs for import() with code cache

[thisalihassan]

• Remove the **Note:** import() does not work when useCodeCache is true. restriction from the API documentation.

Assisted by: Claude Opus 4.6

[nodejs-github-bot]

Review requested:

• @nodejs/single-executable

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 89.81%. Comparing base (de5644c) to head (ead9914).
⚠️ Report is 6 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #62678      +/-   ##
==========================================
- Coverage   89.81%   89.81%   -0.01%     
==========================================
  Files         699      699              
  Lines      216235   216235              
  Branches    41336    41339       +3     
==========================================
- Hits       194216   194206      -10     
- Misses      14129    14141      +12     
+ Partials     7890     7888       -2     

Files with missing lines	Coverage Δ
src/node_sea.cc	89.53% <ø> (ø)

... and 50 files with indirect coverage changes

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