### Godot version

v4.1.stable.official [970459615]

### System information

Windows 11

### Issue description

Using `String::pad_zeros` on a string containing digits with greater length than the argument `digits` raises the error `Parameter count should be a positive number.` of `String::repeat`, because it is called with a negative parameter.
(Actually this error is not 100% correct, it should be non-negative)

4.0 Code:
https://github.com/godotengine/godot/blob/c8e0bd50c57de91c061866db1de407f2e7a74acd/core/string/ustring.cpp#L4127-L4155

Example: `"2023".pad_zeros(2)`
`begin == 0`
`end == 4`
`end - begin < p_digits == false` => No "0" is inserted, the string is returned unchanged.

4.1 Code:
https://github.com/godotengine/godot/blob/ce5c6151fc498b39fe0c188045a4685e0f627854/core/string/ustring.cpp#L4266-L4290

Example: `"2023".pad_zeros(2)`
`begin == 0`
`end == 4`
`zeros_to_add == 2 - (4 - 0) == -2`
=> `s.insert(0, String("0").repeat(-2))` is called => Error.

I don't know why this was changed, but I think ensuring that `zeros_to_add > 0` should be ensured internally and not by the user. If this condition is not fullfilled the string should be returned unchanged as in the 4.0 implementation.

### Steps to reproduce

Try my above mentioned example in 4.0 and 4.1

### Minimal reproduction project

Not necessary.
while (this_substr != r_this_str && that_substr != r_that_str) {
		if (*this_substr < *that_substr) {
			return -1;
		} else if (*this_substr > *that_substr) {
			return 1;
		}
		this_substr++;
		that_substr++;
	}
	return 0;
}
signed char ::naturalcasecmp_to(const  &p_str) const {
	const char32_t *this_str = get_data();
	const char32_t *that_str = p_str.get_data();
	if (this_str && that_str) {
		while (*this_str == '.' || *that_str == '.') {
			if (*this_str++ != '.') {
				return 1;
			}
			if (*that_str++ != '.') {
				return -1;
			}
			if (!*that_str) {
				return 1;
			}
			if (!*this_str) {
				return -1;
			}
		}