### 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.
const char32_t *cstr = get_data();
	 new_string;
	int start_index = 0;
	for (int i = 1; i < this->size(); i++) {
		bool is_prev_upper = is_ascii_upper_case(cstr[i - 1]);
		bool is_prev_lower = is_ascii_lower_case(cstr[i - 1]);
		bool is_prev_digit = is_digit(cstr[i - 1]);
		bool is_curr_upper = is_ascii_upper_case(cstr[i]);
		bool is_curr_lower = is_ascii_lower_case(cstr[i]);
		bool is_curr_digit = is_digit(cstr[i]);
		bool is_next_lower = false;
		if (i + 1 < this->size()) {
			is_next_lower = is_ascii_lower_case(cstr[i + 1]);
		}
		const bool cond_a = is_prev_lower && is_curr_upper; 
		const bool cond_b = (is_prev_upper || is_prev_digit) && is_curr_upper && is_next_lower; 
		const bool cond_c = is_prev_digit && is_curr_lower && is_next_lower; 
		const bool cond_d = (is_prev_upper || is_prev_lower) && is_curr_digit; 
		if (cond_a || cond_b || cond_c || cond_d) {
			new_string += this->substr(start_index, i - start_index) + "_";
			start_index = i;
		}
	}
	new_string += this->substr(start_index, this->size() - start_index);
	return new_string.to_lower();
}
 ::capitalize() const {