### 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.
// Check near char32_t range
	input = "&#xFFFFFFFF;";
	result = input.xml_unescape();
	CHECK(result.length() == 1);
	C);
	input = "&#4294967295;";
	result = input.xml_unescape();
	CHECK(result.length() == 1);
	C);
	// Check out of range of char32_t
	input = "&#xFFFFFFFFF;";
	CHECK(input.xml_unescape() == input);
	input = "&#4294967296;";
	CHECK(input.xml_unescape() == input);
	// Shouldn't consume without ending in a ';'
	input = "&#66";
	CHECK(input.xml_unescape() == input);
	input = "&#x41";
	CHECK(input.xml_unescape() == input);
	// Invalid characters should make the entity ignored
	input = "&#x41SomeIrrelevantText;";
	CHECK(input.xml_unescape() == input);
	input = "&#66SomeIrrelevantText;";
	CHECK(input.xml_unescape() == input);
}
TEST_CASE("[String] Strip escapes") {
	String s = "\t\tTest Test\r\n Test";
	CHECK(s.strip_escapes() == "Test Test Test");
}
TEST_CASE("[String] Similarity") {