fix(material/menu): remove deprecated animation definitions

Deletes publicly-exported animation definitions that were marked for removal in v21.

BREAKING CHANGE:
* `fadeInItems` symbol has been removed.
* `transformMenu` symbol has been removed.
* `matMenuAnimations` symbol has been removed.

Author: crisbeto

goldens/material/menu/index.api.md

@@ -27,9 +27,6 @@ import { ScrollStrategy } from '@angular/cdk/overlay';
 import { Subject } from 'rxjs';
 import { TemplateRef } from '@angular/core';
 
-// @public @deprecated (undocumented)
-export const fadeInItems: any;
-
 // @public
 export const MAT_MENU_CONTENT: InjectionToken<MatMenuContent>;
 
@@ -153,12 +150,6 @@ export class MatMenu implements AfterContentInit, MatMenuPanel<MatMenuItem>, OnI
     static ɵfac: i0.ɵɵFactoryDeclaration<MatMenu, never>;
 }
 
-// @public @deprecated
-export const matMenuAnimations: {
-    readonly transformMenu: any;
-    readonly fadeInItems: any;
-};
-
 // @public
 export class MatMenuContent implements OnDestroy {
     constructor(...args: unknown[]);
@@ -321,9 +312,6 @@ export type MenuPositionX = 'before' | 'after';
 // @public (undocumented)
 export type MenuPositionY = 'above' | 'below';
 
-// @public @deprecated (undocumented)
-export const transformMenu: any;
-
 // (No @packageDocumentation comment for this package)
 
 ```

src/material/menu/BUILD.bazel

@@ -70,7 +70,6 @@ ng_project(
         "context-menu-trigger.ts",
         "index.ts",
         "menu.ts",
-        "menu-animations.ts",
         "menu-content.ts",
         "menu-errors.ts",
         "menu-item.ts",

src/material/menu/menu-animations.ts

@@ -16,7 +16,6 @@ export {
   MENU_PANEL_TOP_PADDING,
 } from './menu-trigger-base';
 export * from './menu-module';
-export * from './menu-animations';
 export * from './menu-positions';
 export * from './menu-panel';
 export {MatContextMenuTrigger} from './context-menu-trigger';