`Curve` emits `changed` signal on scene reload even when no change has happened

Tested versions

Reproducible in 4.6.1.stable

System information

Godot v4.6.1.stable - Windows 11 (build 26200) - Multi-window, 1 monitor - Vulkan (Forward+) - dedicated NVIDIA GeForce GTX 1660 SUPER (NVIDIA; 32.0.15.9186) - Intel(R) Core(TM) i7-10700F CPU @ 2.90GHz (16 threads) - 15.92 GiB memory

Issue description

A Curve's changed signal can emit in the editor even when no change has occurred, leading to unexpected bugs in tool scripts. Specifically, under the following conditions:

• The curve is an exported property of a node in a scene A
• The curve contains at least a point
• Scene A is open in the editor
• Another scene B is also open which contains an instance of scene A
• Scene A is reloaded

Steps to reproduce

• Open both the test and the thing scenes in the attached project.
• Reload the thing scene, and look at the console printout.

Minimal reproduction project (MRP)

bug-report.zip

Start by running the attached minimal reproduction project and opening the test and thing scenes as described. Trace how Curve handles its changed signal while scene A is reloaded with an instance open in scene B. Done means reloading thing no longer prints a change when the curve itself was not modified.