Bump ember-cli-htmlbars from 6.2.0 to 6.3.0

Bumps [ember-cli-htmlbars](https://github.com/ember-cli/ember-cli-htmlbars) from 6.2.0 to 6.3.0.
- [Release notes](https://github.com/ember-cli/ember-cli-htmlbars/releases)
- [Changelog](https://github.com/ember-cli/ember-cli-htmlbars/blob/master/CHANGELOG.md)
- [Commits](ember-cli/ember-cli-htmlbars@v6.2.0...v6.3.0)

---
updated-dependencies:
- dependency-name: ember-cli-htmlbars
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

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