### Tested versions

- Reproducible in: v4.2.stable.official [46dc27791]
- Not reproducible in: v4.1.3.stable

### System information

Godot v4.2.stable - Windows 10.0.22621 - Vulkan (Forward+) - dedicated AMD Radeon RX 6600 (Advanced Micro Devices, Inc.; 31.0.21023.2010) - AMD Ryzen 7 5700X 8-Core Processor (16 Threads)

### Issue description

Starting with Godot 4.2, changing a Control node's anchor offsets with an AnimationPlayer node results in the offsets "snapping" to the keyframes, as if Nearest interpolation were used. 

This only applies to the Linear Interpolation Mode; Cubic still works as expected.

![resize_interp_fail](https://github.com/godotengine/godot/assets/26508550/a10a973f-afdc-45f2-986c-594aa3cdc9dc)

I encountered this regression when upgrading my project from 4.1.3 to 4.2. Minimum reproduction project provided below.

### Steps to reproduce

- Create a Control node with a Custom anchor preset.
- Create an AnimationPlayer track for one or more of its anchor offsets, with the Continuous update mode and Linear interpolation.
- Add keyframes to track(s)
- Play animation (either in the editor or in-game)

### Minimal reproduction project (MRP)

[ControlResize.zip](https://github.com/godotengine/godot/files/13589517/ControlResize.zip)

const Plane pa = a.operator Plane();
			const Plane pb = b.operator Plane();
			return Plane(pa.normal + pb.normal, pa.d + pb.d);
		} break;
		case Variant::AABB: {
			const ::AABB aa = a.operator ::AABB();
			const ::AABB ab = b.operator ::AABB();
			return ::AABB(aa.position + ab.position, aa.size + ab.size);
		} break;
		case Variant::BASIS: {
			return (a.operator Basis()) * (b.operator Basis());
		} break;
		case Variant::QUATERNION: {
			return (a.operator Quaternion()) * (b.operator Quaternion());
		} break;
		case Variant::TRANSFORM2D: {
			return (a.operator Transform2D()) * (b.operator Transform2D());
		} break;
		case Variant::TRANSFORM3D: {
			return (a.operator Transform3D()) * (b.operator Transform3D());
		} break;
		case Variant::INT:
		case Variant::RECT2I:
		case Variant::VECTOR2I:
		case Variant::VECTOR3I:
		case Variant::VECTOR4I:
		case Variant::PACKED_INT32_ARRAY:
		case Variant::PACKED_INT64_ARRAY: {
			
			return cast_from_blendwise(add_variant(cast_to_blendwise(a), cast_to_blendwise(b)), a.get_type());