build(deps): bump http-proxy-middleware and @edx/frontend-build

Bumps [http-proxy-middleware](https://github.com/chimurai/http-proxy-middleware) to 2.0.7 and updates ancestor dependency [@edx/frontend-build](https://github.com/openedx/frontend-build). These dependencies need to be updated together.


Updates `http-proxy-middleware` from 2.0.6 to 2.0.7
- [Release notes](https://github.com/chimurai/http-proxy-middleware/releases)
- [Changelog](https://github.com/chimurai/http-proxy-middleware/blob/v2.0.7/CHANGELOG.md)
- [Commits](chimurai/http-proxy-middleware@v2.0.6...v2.0.7)

Updates `@edx/frontend-build` from 8.0.6 to 13.0.14
- [Release notes](https://github.com/openedx/frontend-build/releases)
- [Commits](openedx/frontend-build@v8.0.6...v13.0.14)

---
updated-dependencies:
- dependency-name: http-proxy-middleware
  dependency-type: indirect
- dependency-name: "@edx/frontend-build"
  dependency-type: direct:production
...

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