Bump mymindstorm/setup-emsdk from 14 to 15 (#5131)

Bumps [mymindstorm/setup-emsdk](https://github.com/mymindstorm/setup-emsdk) from 14 to 15.
- [Release notes](https://github.com/mymindstorm/setup-emsdk/releases)
- [Commits](https://github.com/mymindstorm/setup-emsdk/compare/6ab9eb1bda2574c4ddb79809fc9247783eaf9021...667eb33f24e84e7f362c16d8d7fff0629a73e15e)

---
updated-dependencies:
- dependency-name: mymindstorm/setup-emsdk
  dependency-version: '15'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>