### 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.
}
	return true; // TODO: Use the parser below for this instead
}
template <class C>
static double built_in_strtod(
		/* A decimal ASCII floating-point number,
		 * optionally preceded by white space. Must
		 * have form "-I.FE-X", where I is the integer
		 * part of the mantissa, F is the fractional
		 * part of the mantissa, and X is the
		 * exponent. Either of the signs may be "+",
		 * "-", or omitted. Either I or F may be
		 * omitted, or both. The decimal point isn't
		 * necessary unless F is present. The "E" may
		 * actually be an "e". E and X may both be
		 * omitted (but not just one). */
		const C *string,
		/* If non-nullptr, store terminating Cacter's
		 * address here. */
		C **endPtr = nullptr) {
	/* Largest possible base 10 exponent. Any
	 * exponent larger than this will already
	 * produce underflow or overflow, so there's
	 * no need to worry about additional digits. */
	static const int maxExponent = 511;
	/* Table giving binary powers of 10. Entry
	 * is 10^2^i. Used to convert decimal
	 * exponents into floating-point numbers. */
	static const double powersOf10[] = {
		10.,