build(docs-infra): remove the dependency on rxjs-compat (#19795)

PR Close #19795

aio/src/app/custom-elements/code/pretty-printer.service.ts

@@ -2,8 +2,6 @@ import { Injectable } from '@angular/core';
 
 import { from as fromPromise, Observable } from 'rxjs';
 import { first, map, share } from 'rxjs/operators';
-import 'rxjs/add/operator/map';
-import 'rxjs/add/operator/share';
 
 import { Logger } from 'app/shared/logger.service';
 

aio/src/app/custom-elements/toc/toc.component.ts

@@ -1,7 +1,6 @@
 import { AfterViewInit, Component, ElementRef, OnDestroy, OnInit, QueryList, ViewChildren } from '@angular/core';
 import { asapScheduler as asap, combineLatest, Subject } from 'rxjs';
 import { startWith, subscribeOn, takeUntil } from 'rxjs/operators';
-import 'rxjs/add/operator/startWith';
 
 import { ScrollService } from 'app/shared/scroll.service';
 import { TocItem, TocService } from 'app/shared/toc.service';

aio/src/app/documents/document.service.ts

@@ -3,7 +3,6 @@ import { HttpClient, HttpErrorResponse } from '@angular/common/http';
 
 import { AsyncSubject, Observable, of } from 'rxjs';
 import { catchError, switchMap, tap } from 'rxjs/operators';
-import 'rxjs/add/operator/do';
 
 import { DocumentContents } from './document-contents';
 export { DocumentContents } from './document-contents';