### 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 (length() == 0) {
		return 0;
	}
	int to = (find(".") >= 0) ? find(".") : length();
	int64_t integer = 0;
	int64_t sign = 1;
	for (int i = 0; i < to; i++) {
		char32_t c = operator[](i);
		if (is_digit(c)) {
			bool overflow = (integer > INT64_MAX / 10) || (integer == INT64_MAX / 10 && ((sign == 1 && c > '7') || (sign == -1 && c > '8')));
			ERR_FAIL_COND_V_MSG(overflow, sign == 1 ? INT64_MAX : INT64_MIN, "Cannot represent " + *this + " as a 64-bit signed integer, since the value is " + (sign == 1 ? "too large." : "too small."));
			integer *= 10;
			integer += c - '0';
		} else if (integer == 0 && c == '-') {
			sign = -sign;
		}
	}
	return integer * sign;
}
int64_t ::to_int(const char *p_str, int p_len) {
	int to = 0;
	if (p_len >= 0) {
		to = p_len;
	} else {
		while (p_str[to] != 0 && p_str[to] != '.') {
			to++;
		}
	}
	int64_t integer = 0;
	int64_t sign = 1;