feat: updated transform methods to return price as string

Author: DzoeL123

apps/signal/54-pipe-observable-to-signal/src/app/currency.pipe.ts

@@ -1,5 +1,4 @@
 import { inject, Pipe, PipeTransform } from '@angular/core';
-import { map, Observable } from 'rxjs';
 import { CurrencyService } from './currency.service';
 
 @Pipe({
@@ -9,7 +8,7 @@ import { CurrencyService } from './currency.service';
 export class CurrencyPipe implements PipeTransform {
   currencyService = inject(CurrencyService);
 
-  transform(price: number): Observable<string> {
-    return this.currencyService.symbol$.pipe(map((s) => `${price}${s}`));
+  transform(price: number): string {
+    return `${price}${this.currencyService.symbol()}`;
   }
 }