How can Stripe extension create contact sub-type?
Depending on your configuration, you can do this with CiviRules.

Your trigger will be Contribution is added, and your action will be Set subtype for contact.

The question is the "condition".  If Stripe is your only payment processor, then you're golden!  The condition should be Contribution is (not) paid by, and set credit card/debit card as the values.