Add mat2 uniform support to WebGL setUniform, fixing silent no-op (#8…

[harshiltewari2004]

Resolves #8939

Changes

• Added the missing FLOAT_MAT2 case to the setUniform switch in
  src/webgl/utils.js (gl.uniformMatrix2fv), mirroring the existing
  mat3/mat4 cases — completing part of the //@todo
• Added FLOAT_MAT2 to the isArray classification in
  getWebGLUniformMetadata, so mat2 uniforms take the array path in
  p5.Shader's value caching
• Added a visual regression test (createFilterShader with a uniform mat2
  driving the fragment color from the matrix diagonal). Verified the test
  fails on unfixed code and passes with the fix.

Note: there was previously no direct setUniform test coverage for matrix
uniforms of any size, in either backend — this test establishes the pattern.
mat2 remains untested on the WebGPU side (where it already works); happy to
add a WGSL counterpart in a follow-up if wanted.

While verifying with a full test run, I hit an intermittent failure in
Typography > textWeight > can control non-variable fonts — unrelated to
this change (2D-mode test, no path to the modified code; passes repeatedly
in isolation on this branch). It loads its font from Google Fonts at test
time, which is the likely flake source.

PR Checklist

• npm run lint passes
• [Inline reference] is included / updated — N/A, no documented API change
• [Unit tests] are included / updated

[p5-bot]

Continuous Release

CDN link

• https://raw.esm.sh/pr/p5@97fdc84/lib/p5.min.js

Published Packages

• https://pkg.pr.new/p5@97fdc84

Commit hash: db05648

Previous deployments

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