refactor: Replace eigen with ml-matrix

[samestep]

Description

In a similar spirit to #896, this PR replaces our dependency on eigen with ml-matrix (found by @joshsunshine), which:

• is more actively maintained than eigen
• has its own type declarations (see Add type declarations BertrandBev/eigen-js#37 (comment))
• doesn't require an await ready step
• has nicer type declarations than mathjs

Running .github/bench.sh on ea9d7ea showed improved performance on all diagrams in our registry; running it on bd01bd0 showed improve performance on all but one (diagrams/incenter-triangle-euclidean.svg). I'm guessing that one is just due to noise.

Checklist

• I have commented my code, particularly in hard-to-understand areas
• My changes generate no new ESLint warnings
• I have reviewed any generated changes to the diagrams/ folder

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[codecov]

Codecov Report

Merging #954 (f35474d) into main (4c428cf) will decrease coverage by 0.08%.
The diff coverage is 91.66%.

❗ Current head f35474d differs from pull request most recent head bd01bd0. Consider uploading reports for the commit bd01bd0 to get more accurate results

@@            Coverage Diff             @@
##             main     #954      +/-   ##
==========================================
- Coverage   63.19%   63.10%   -0.09%     
==========================================
  Files          62       62              
  Lines        7930     7912      -18     
  Branches     1827     1826       -1     
==========================================
- Hits         5011     4993      -18     
  Misses       2795     2795              
  Partials      124      124              

Impacted Files	Coverage Δ
packages/core/src/engine/Optimizer.ts	81.41% <91.30%> (-0.75%)	⬇️
packages/core/src/index.ts	70.06% <100.00%> (-0.41%)	⬇️

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