### 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.
}
				} else {
					// 
					for (int i = 2; i < p_src_len; i++) {
						eat = i + 1;
						char32_t ct = p_src[i];
						if (ct == ';' || !is_digit(ct)) {
							break;
						}
					}
					if (p_src[eat - 1] == ';') {
						int64_t val = ::to_int(p_src + 2, eat - 3);
						if (val > 0 && val <= UINT32_MAX) {
							c = (char32_t)val;
						} else {
							overflow = true;
						}
					}
				}
				// 
				// 
				if (c == '\0' || overflow || p_src[eat - 1] != ';') {
					eat = 1;
					c = *p_src;
				}
				if (p_dst) {
					*p_dst = c;
				}
			} else if (p_src_len >= 4 && p_src[1] == 'g' && p_src[2] == 't' && p_src[3] == ';') {
				if (p_dst) {