build(deps-dev): bump @types/ember__routing from 4.0.12 to 4.0.21

Bumps [@types/ember__routing](https://github.com/DefinitelyTyped/DefinitelyTyped/tree/HEAD/types/ember__routing) from 4.0.12 to 4.0.21.
- [Release notes](https://github.com/DefinitelyTyped/DefinitelyTyped/releases)
- [Changelog](https://github.com/DefinitelyTyped/DefinitelyTyped/blob/master/types/ember__routing/history-location.d.ts)
- [Commits](https://github.com/DefinitelyTyped/DefinitelyTyped/commits/HEAD/types/ember__routing)

---
updated-dependencies:
- dependency-name: "@types/ember__routing"
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]