refactor: Clean up imports and unused variables in ticket-related components

- Remove unused imports from PurchaseTicketDialog.vue and useUserTickets.ts for improved code clarity.
- Update events.ts to eliminate the unused paymentRequest parameter in payInvoiceWithWallet function.
- Simplify MyTickets.vue by removing the unused unregisteredTickets variable and related QR code generation logic, enhancing maintainability.

src/lib/api/events.ts

@@ -1,4 +1,4 @@
-import type { Event, EventsApiError, Ticket } from '../types/event'
+import type { Event, Ticket } from '../types/event'
 import { config } from '@/lib/config'
 import { lnbitsAPI } from './lnbits'
 
@@ -72,7 +72,7 @@ export async function purchaseTicket(eventId: string): Promise<{ payment_hash: s
   }
 }
 
-export async function payInvoiceWithWallet(paymentRequest: string, walletId: string, adminKey: string): Promise<{ payment_hash: string; fee_msat: number; preimage: string }> {
+export async function payInvoiceWithWallet(paymentRequest: string, _walletId: string, adminKey: string): Promise<{ payment_hash: string; fee_msat: number; preimage: string }> {
   try {
     const response = await fetch(
       `${API_BASE_URL}/api/v1/payments`,