Fix offscreencanvas undefined

[yuriha-chan]

What

Fixes #11016
burahaで描画時にブラウザがOffscreenCanvasに対応していない場合に、エラーをcatchして未対応と報告する

Why

Additional info (optional)

iOSやMac端末を持っていないので、Chromeからの閲覧でエラーが生じないことのみチェックしています。

Checklist

• [ x ] Read the contribution guide
• [ x ] Test working in a local environment (partially)
• (If needed) Add story of storybook
• (If needed) Update CHANGELOG.md
• (If possible) Add tests

[codecov]

Codecov Report

Merging #11017 (9e43ef4) into develop (f5dfb64) will decrease coverage by 0.19%.
The diff coverage is 100.00%.

@@             Coverage Diff             @@
##           develop   #11017      +/-   ##
===========================================
- Coverage    77.47%   77.29%   -0.19%     
===========================================
  Files          909      907       -2     
  Lines        91516    91361     -155     
  Branches      6890     7512     +622     
===========================================
- Hits         70904    70619     -285     
- Misses       20612    20742     +130     

Impacted Files	Coverage Δ
packages/frontend/src/workers/test-webgl2.ts	85.71% <100.00%> (-14.29%)	⬇️

... and 23 files with indirect coverage changes

[syuilo]

🙏