### 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)

int len = _find(p_keys, length) + 1; 
	if (len <= 0) {
		
		
		if (p_ok) {
			*p_ok = false;
		}
		return T();
	} else if (len == 1) { 
		if (p_ok) {
			*p_ok = true;
		}
		return p_keys[0].value;
	}
	int idx = _find(p_keys, p_time, p_backward);
	ERR_FAIL_COND_V(idx == -2, T());
	int maxi = len - 1;
	bool is_start_edge = idx == -1;
	bool is_end_edge = p_backward ? idx == 0 : idx >= maxi;
	real_t c = 0.0;
	
	real_t delta = 0.0;
	real_t from = 0.0;
	int pre = -1;
	int next = -1;
	int post = -1;