Fix animation tree editor crash

[Nazarwadim]

Fixes: #102374

It crashes because the map referenced memory that was reallocated.

godot/scene/animation/animation_tree.cpp

Line 779 in eee39f0

input_activity_map_get[String(p_base_path).substr(0, String(p_base_path).length() - 1)] = &input_activity_map[p_base_path];

[AThousandShips]

I think the fact that this is because of an incompatibility of the container behavior I would suggest reverting the previous change and investigating it again

The change is one of a iterator-stable container to one that isn't, which I think warrants some further testing (same with any other changes involving this kind of change)

[Nazarwadim]

Sure. I'll do that in 4.5.

[eddieataberk]

Just tested it. This commit does fixes the crash.

[AThousandShips]

Good, worth reimplementing the changes in 4.5

[a-johnston]

FYI there's a different crash caused by the original PR in AnimationNodeBlendTree::rename_node from adding a new node to an existing tree and renaming it. There may be another factor however as I can consistently get the crash with a more involved tree but not on a simpler one. I think the speedups offered by the PR would be good but it seems like there are some things to work out.