production build breaks ember-inspector component tab

[patricklx]

relevant issue: emberjs/ember-inspector#2125

here is definition how it should work:
https://github.com/emberjs/ember.js/blob/master/packages/%40ember/-internals/environment/lib/env.ts#L129

relevant code in inspector
https://github.com/emberjs/ember-inspector/blob/main/skeletons/web-extension/boot.js#L13
https://github.com/emberjs/ember-inspector/blob/main/ember_debug/libs/capture-render-tree.js#L10

embroider just overwrites EmberEnv:
https://github.com/embroider-build/embroider/blob/main/packages/core/src/app.ts#L293

[void-mAlex]

this fix breaks ie11 compatibility for ember 3.28.11+ which embroider supports
as it doesn't get trasnpiled by babel at all
options that I see are:

1. cater for that specific flag very explicitly
2. write the minimum loop needed to act like Object.assign like the suggestion on the pr that fixed this extend existing EmberENV for ember-inspector #1252 (comment)
3. check for an object already on the window and amend it appropriately with our values
4. something else

cc @ef4 when you have the time we can discuss the cleanest fix