chore(deps): update dependency ember-source to v3.28.6

[renovate[bot]]

This PR contains the following updates:

Package	Change	Age	Adoption	Passing	Confidence
ember-source (source)	3.28.5 -> 3.28.6

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Release Notes

emberjs/ember.js

### [`v3.28.6`](https://togithub.com/emberjs/ember.js/compare/v3.28.5...v3.28.6) [Compare Source](https://togithub.com/emberjs/ember.js/compare/v3.28.5...v3.28.6)

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