fix import @pixi/math/src to @pixi/math

[zxc122333]

Description of change

fix import @pixi/math/src to @pixi/math

Pre-Merge Checklist

• Lint process passed (npm run lint)
• Tests passed (npm run test)

[codecov-io]

Codecov Report

Merging #6483 into dev will not change coverage by %.
The diff coverage is n/a.

@@           Coverage Diff           @@
##              dev    #6483   +/-   ##
=======================================
  Coverage   80.14%   80.14%           
=======================================
  Files          57       57           
  Lines        2825     2825           
=======================================
  Hits         2264     2264           
  Misses        561      561           

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update dbff69b...0518a54. Read the comment docs.

[bigtimebuddy]

Thank you!