### 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.
if (p_string.is_empty()) {
		return 0;
	}
	int len = length();
	int slen = p_string.length();
	if (len < slen) {
		return 0;
	}
	 str;
	if (p_from >= 0 && p_to >= 0) {
		if (p_to == 0) {
			p_to = len;
		} else if (p_from >= p_to) {
			return 0;
		}
		if (p_from == 0 && p_to == len) {
			str = ();
			str.copy_from_unchecked(&get_data()[0], len);
		} else {
			str = substr(p_from, p_to - p_from);
		}
	} else {
		return 0;
	}
	int c = 0;
	int idx = -1;
	do {
		idx = p_case_insensitive ? str.findn(p_string) : str.find(p_string);
		if (idx != -1) {
			str = str.substr(idx + slen, str.length() - slen);