### Godot version

4.1.1

### System information

linux

### Issue description

The `"%+f"` format adds a `+` sign in front of positive numbers. If you try to format `-0.0`, it breaks and displays both a `+` and a `-`.

### Steps to reproduce

```gdscript
@tool
extends EditorScript

func _run() -> void:
    print("%+f" % -0.0)
```

### Minimal reproduction project

see above
}
		p += 1;
	}
	/*
	 * Now suck up the digits in the mantissa. Use two integers to collect 9
	 * digits each (this is faster than using floating-point). If the mantissa
	 * has more than 18 digits, ignore the extras, since they can't affect the
	 * value anyway.
	 */
	pExp = p;
	p -= mantSize;
	if (decPt < 0) {
		decPt = mantSize;
	} else {
		mantSize -= 1; /* 
	}
	if (mantSize > 18) {
		fracExp = decPt - 18;
		mantSize = 18;
	} else {
		fracExp = decPt - mantSize;
	}
	if (mantSize == 0) {
		fraction = 0.0;
		p = string;
		goto done;
	} else {
		int frac1, frac2;
		frac1 = 0;
		for (; mantSize > 9; mantSize -= 1) {