### Godot version

4.0.dev (c309de53997feff3286295fb2d71657f112a15db)

### System information

Linux, Nvidia, Vulkan

### Issue description

Editor segfaults when certain conditions are met when using the AnimationPlayer editor.

### Steps to reproduce

1. Create multiple animations, saved into a animation collection
2. Open an existing animation, then make a new empty animation
3. Change from seconds to fps, or add a new property to animate ()
4. Editor crashes

NOTE: It is slightly random and I have not found a perfect repro

### Minimal reproduction project

N/A (TBD?)
r_ret = d["method"];
						return true;
					}
					ERR_FAIL_COND_V(!d.has("args"), false);
					Vector<Variant> args = d["args"];
					if (name == "arg_count") {
						r_ret = args.size();
						return true;
					}
					if (name.begins_with("args/")) {
						int idx = name.get_slice("/", 1).to_int();
						ERR_FAIL_INDEX_V(idx, args.size(), false);
						String what = name.get_slice("/", 2);
						if (what == "type") {
							r_ret = args[idx].get_type();
							return true;
						}
						if (what == "value") {
							r_ret = args[idx];
							return true;
						}
					}
				} break;
				case Animation::TYPE_BEZIER: {
					if (name == "value") {
						r_ret = animation->bezier_track_get_key_value(track, key);
						return true;
					}
					if (name == "in_handle") {
						r_ret = animation->bezier_track_get_key_in_handle(track, key);