chore(vant-compat): use Rslib to build

[chenjiahan]

This pull request includes several changes to the vant-compat package to update its build configuration and dependencies. The most important changes involve modifying the build scripts, updating dependencies, and adding a new configuration file for rslib.

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 89.69%. Comparing base (6dc6b4b) to head (e8a6f51).
Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #13231      +/-   ##
==========================================
+ Coverage   89.66%   89.69%   +0.02%     
==========================================
  Files         257      257              
  Lines        7013     7013              
  Branches     1736     1736              
==========================================
+ Hits         6288     6290       +2     
+ Misses        382      380       -2     
  Partials      343      343              

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