fix(material/sidenav): remove deprecated animation definitions

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

BREAKING CHANGE:
* `matDrawerAnimations` symbol has been removed.

Author: crisbeto

goldens/material/sidenav/index.api.md

@@ -69,11 +69,6 @@ export class MatDrawer implements AfterViewInit, OnDestroy {
     static ɵfac: i0.ɵɵFactoryDeclaration<MatDrawer, never>;
 }
 
-// @public @deprecated
-export const matDrawerAnimations: {
-    readonly transformDrawer: any;
-};
-
 // @public
 export class MatDrawerContainer implements AfterContentInit, DoCheck, OnDestroy {
     constructor(...args: unknown[]);

src/material/sidenav/BUILD.bazel

@@ -66,7 +66,6 @@ ng_project(
     name = "sidenav",
     srcs = [
         "drawer.ts",
-        "drawer-animations.ts",
         "index.ts",
         "public-api.ts",
         "sidenav.ts",

src/material/sidenav/drawer-animations.ts

@@ -18,4 +18,3 @@ export {
   MatDrawerMode,
 } from './drawer';
 export * from './sidenav';
-export * from './drawer-animations';