Unset "shop_cipher" from "Create Custom Brands" request

[alvgalrus]

Hello, and thank you for the library!

When I tried to createCustomBrand($name), I got an error with the message shop_cipher is not allowed in this api. I see there's already a condition for that in the Client:

tiktokshop-php/src/Client.php

Lines 175 to 178 in b9564e2

	if (preg_match('/^\/product\/(\d{6})\/(global_products|files\/upload|images\/upload)/', $uri->getPath())
	|| preg_match('/^\/(authorization|seller)\/(\d{6})\//', $uri->getPath())) {
	unset($query['shop_cipher']);
	}

This PR unsets shop_cipher when POST'ing to that endpoint. The GET one still needs it following the documentation:

• Get Brands
• Create Custom Brands

Regards,
Álvaro

[nVuln]

I already merged and tagged new version to this PR
thanks for your contribution