Bump ember-page-title from 5.1.0 to 5.2.1

Bumps [ember-page-title](https://github.com/adopted-ember-addons/ember-page-title) from 5.1.0 to 5.2.1.
- [Release notes](https://github.com/adopted-ember-addons/ember-page-title/releases)
- [Changelog](https://github.com/adopted-ember-addons/ember-page-title/blob/master/CHANGELOG.md)
- [Commits](ember-cli/ember-page-title@5.1.0...v5.2.1)

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

Author: dependabot-preview[bot]