### 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.
// and the same second as "ÿ" (\u00ff)
	STRIP_TEST(String::utf8("¿").lstrip(String::utf8("qwaµÿjkl")) == String::utf8("¿"));
	STRIP_TEST(String::utf8("¿").rstrip(String::utf8("qwaµÿjkl")) == String::utf8("¿"));
	STRIP_TEST(String::utf8("µ¿ÿ").lstrip(String::utf8("qwaµÿjkl")) == String::utf8("¿ÿ"));
	STRIP_TEST(String::utf8("µ¿ÿ").rstrip(String::utf8("qwaµÿjkl")) == String::utf8("µ¿"));
	CHECK(state);
#undef STRIP_TEST
}
TEST_CASE("[String] Ensuring empty string into parse_utf8 passes empty string") {
	String empty;
	CHECK(empty.parse_utf8(nullptr, -1) == ERR_INVALID_DATA);
}
TEST_CASE("[String] Cyrillic to_lower()") {
	String upper = String::utf8("АБВГДЕЁЖЗИЙКЛМНОПРСТУФХЦЧШЩЪЫЬЭЮЯ");
	String lower = String::utf8("абвгдеёжзийклмнопрстуфхцчшщъыьэюя");
	String test = upper.to_lower();
	bool state = test == lower;
	CHECK(state);
}
TEST_CASE("[String] Count and countn functionality") {
#define COUNT_TEST(x)             \
	{                             \
		bool success = x;         \
		state = state && success; \
	}
	bool state = true;
	COUNT_TEST(String("").count("Test") == 0);
	COUNT_TEST(String("Test").count("") == 0);
	COUNT_TEST(String("Test").count("test") == 0);