chore: remove unused type argument

Author: benlesh

api_guard/dist/types/operators/index.d.ts

@@ -86,7 +86,7 @@ export declare function distinctUntilChanged<T, K>(comparator: (previous: K, cur
 export declare function distinctUntilKeyChanged<T>(key: keyof T): MonoTypeOperatorFunction<T>;
 export declare function distinctUntilKeyChanged<T, K extends keyof T>(key: K, compare: (x: T[K], y: T[K]) => boolean): MonoTypeOperatorFunction<T>;
 
-export declare function elementAt<T, D>(index: number): MonoTypeOperatorFunction<T>;
+export declare function elementAt<T>(index: number): MonoTypeOperatorFunction<T>;
 export declare function elementAt<T, D>(index: number, defaultValue: D): OperatorFunction<T, T | D>;
 
 export declare function endWith<T>(scheduler: SchedulerLike): MonoTypeOperatorFunction<T>;

src/internal/operators/elementAt.ts

@@ -6,7 +6,7 @@ import { throwIfEmpty } from './throwIfEmpty';
 import { defaultIfEmpty } from './defaultIfEmpty';
 import { take } from './take';
 
-export function elementAt<T, D>(index: number): MonoTypeOperatorFunction<T>;
+export function elementAt<T>(index: number): MonoTypeOperatorFunction<T>;
 export function elementAt<T, D>(index: number, defaultValue: D): OperatorFunction<T, T | D>;
 
 /**