Fix ember-try 4.4 scenario, add latest LTS

[BlueCutOfficial]

This PR makes changes in ember-try config:

• It fixes tests for 4.4 scenario: ember-qunit release note mentions that version 8+ requires Ember 4.8, so an application using Ember 4.4 would rely on ember-qunit 7 or less.
• It adds the latest LTS 5.8 and 5.12 and runs these scenarios on CI.

@elwayman02, I know you mentioned that you may prefer to remove the 4.4 scenario in the end. I preferred to fix it here so I don't introduce any breaking changes in the versions you officially support.

[BlueCutOfficial]

Closing in favor of #1273 since overall the changes are not that big.