### 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.
#ifdef WINDOWS_ENABLED
	
	parse_utf16((const char16_t *)p_cstr, p_clip_to);
#else
	
	copy_from((const char32_t *)p_cstr, p_clip_to);
#endif
}
void ::copy_from(const char32_t &p_char) {
	if (p_char == 0) {
		print_unicode_error("NUL character", true);
		return;
	}
	resize(2);
	char32_t *dst = ptrw();
	if ((p_char & 0xfffff800) == 0xd800) {
		print_unicode_error(vformat("Unpaired surrogate (%x)", (uint32_t)p_char));
		dst[0] = _replacement_char;
	} else if (p_char > 0x10ffff) {
		print_unicode_error(vformat("Invalid unicode codepoint (%x)", (uint32_t)p_char));
		dst[0] = _replacement_char;
	} else {
		dst[0] = p_char;
	}
	dst[1] = 0;
}
void ::copy_from(const char32_t *p_cstr) {