### Godot version

4.2.beta.custom_build [51f81e1c8]

### System information

macOS 11.0+

### Issue description

I could sense a recent merging of a few pull requests on here:

<img width="865" alt="image" src="https://github.com/godotengine/godot/assets/1129695/1cf7d144-a4d2-4514-abca-1405222e702a">

This bug has the following related merges as the most recent ones:

https://github.com/godotengine/godot/pull/80813
https://github.com/godotengine/godot/pull/80939

The pull requests are for reviving onion-skinning capabilities, but this causes a minor unexpected result (see Steps to reproduce)



### Steps to reproduce

## A. Use 4.2.beta.custom_build [51f81e1c8]

1. Obtain the attached minimal reproduction project
2. Select the AnimationPlayer node
<img width="1468" alt="image" src="https://github.com/godotengine/godot/assets/1129695/ca16d7a6-7690-45b4-b8f9-b12fded64ca4">
3. In the Animation panel, click "Edit" to find your shortcuts for "Go to Next Step" and "Go to Previous Step"
<img width="410" alt="image" src="https://github.com/godotengine/godot/assets/1129695/a708e196-2eb9-42ea-bf0e-fd0aa88a9e60">
4. Use the shortcuts to spam go back and forth the animation

Expected result: animation goes smoothly

https://github.com/godotengine/godot/assets/1129695/c24c498c-7f77-4cc9-a1c9-a1627d89c58b



Actual result: animation jumps crazily


https://github.com/godotengine/godot/assets/1129695/947bf5b4-a0ab-42d4-bb5b-201800b4bdc6


https://github.com/godotengine/godot/assets/1129695/65303cd0-8c2d-4a35-9d16-c94752ac2e3a




## B. My successful yet unverified fix attempt on 4.2.beta.custom_build [51f81e1c8]

Either by:

<img width="831" alt="image" src="https://github.com/godotengine/godot/assets/1129695/80d167ae-27e7-4ec4-a4c9-ffc7adc0353f">


Or by:

<img width="806" alt="image" src="https://github.com/godotengine/godot/assets/1129695/2bae8697-8ef3-48dc-9f0a-2b5fe568ed43">


I don't see any negative impact on Onion Skinning or other functions by the above fix attempt, but I am not sure, I need someone to help me verify this.



### Minimal reproduction project

[gd_anim_unittest_1.zip](https://github.com/godotengine/godot/files/12909805/gd_anim_unittest_1.zip)






const int max_sc_width = String::num(max_sc).length() * max_digit_width;
			while (!step_found) {
				int min = max_sc_width;
				if (decimals > 0) {
					min += period_width + max_digit_width * decimals;
				}
				static const int _multp[3] = { 1, 2, 5 };
				for (int i = 0; i < 3; i++) {
					step = (_multp[i] * dec);
					if (step * scale / SC_ADJ > min) {
						step_found = true;
						break;
					}
				}
				if (step_found) {
					break;
				}
				dec *= 10;
				decimals--;
				if (decimals < 0) {
					decimals = 0;
				}
			}
			if (use_fps) {
				float step_size = animation->get_step();
				if (step_size > 0) {
					int prev_frame_ofs = -10000000;
					for (int i = 0; i < zoomw; i++) {
						float pos = get_value() + double(i) / scale;
						float prev = get_value() + (double(i) - 1.0) / scale;