Cached cctype results in non-random data

[codingconcepts]

Issue: The first time faker.CCType() is called, the value is internally cached, meaning subsequent calls will always return the same data:

https://github.com/go-faker/faker/blob/5effebba7fe9e25350305432ffdca5e19151edad/payment.go#L31

Fix: Remove the caching to ensure subsequent calls are sufficiently random.

[unrealhoang]

also this will result in data race issue if multiple faker.CCType() being called for the first time in parallel