Prepare Release v4.15.0

[github-actions]

This PR is a preview of the release that release-plan has prepared. To release you should just merge this PR 👍

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Release (2025-11-19)

• ember-inspector 4.15.0 (minor)

🚀 Enhancement

• ember-inspector
  • #2694 link to legacy inspector support docs (@patricklx)

🐛 Bug Fix

• ember-inspector
  • #2691 fix data tab not showing models (@patricklx)
  • #2703 regression: fix _backburner access (@patricklx)
  • #2705 fix whats new for nightly (@patricklx)
  • #2689 fix loading race condition (@patricklx)
  • #2700 add a optional chaining operator for accessing getOwner on application (@mansona)
  • #2702 add back iframe (without src) support (@patricklx)
  • #2692 fix whats new (@patricklx)

🏠 Internal

• ember-inspector
  • #2708 update release-plan workflows to new format (@mansona)

Committers: 2

• Chris Manson (@mansona)
• Patrick Pircher (@patricklx)