remove duplicate function

ts/client/src/accounts/group.ts

@@ -455,16 +455,6 @@ export class Group {
     return serum3Market;
   }
 
-  public getSerum3MarketByPk(pk: PublicKey): Serum3Market | undefined {
-    const serum3Market = Array.from(
-      this.serum3MarketsMapByExternal.values(),
-    ).find((serum3Market) => serum3Market.serumMarketExternal.equals(pk));
-    if (!serum3Market) {
-      throw new Error(`No serum3Market found by public key ${pk}!`);
-    }
-    return serum3Market;
-  }
-
   public getSerum3MarketByExternalMarket(
     externalMarketPk: PublicKey,
   ): Serum3Market {