build(deps-dev): bump msw in /build/frontend-legacy

Bumps [msw](https://github.com/mswjs/msw) from 2.12.4 to 2.12.6.
- [Release notes](https://github.com/mswjs/msw/releases)
- [Changelog](https://github.com/mswjs/msw/blob/main/CHANGELOG.md)
- [Commits](mswjs/msw@v2.12.4...v2.12.6)

---
updated-dependencies:
- dependency-name: msw
  dependency-version: 2.12.6
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]