fix(Webauthn): remove duplicated property

Author: Ansonhkg

packages/auth-services/src/auth-server/src/schemas/AuthServiceMintRequestSchema.ts

@@ -29,7 +29,6 @@ export const tAuthServiceMintRequestSchema = t.Object({
   authMethodType: t.String(),
   authMethodId: t.String(),
   pubkey: t.Optional(t.String()),
-  pubkey: t.Optional(t.String({ default: '0x' })),
   scopes: t.Optional(
     t.Array(
       t.Union([