fix(material/sort): remove deprecated animation definitions

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

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

Author: crisbeto

goldens/material/sort/index.api.md

@@ -80,16 +80,6 @@ export interface MatSortable {
     start: SortDirection;
 }
 
-// @public @deprecated
-export const matSortAnimations: {
-    readonly indicator: any;
-    readonly leftPointer: any;
-    readonly rightPointer: any;
-    readonly arrowOpacity: any;
-    readonly arrowPosition: any;
-    readonly allowChildren: any;
-};
-
 // @public
 export interface MatSortDefaultOptions {
     arrowPosition?: SortHeaderArrowPosition;

src/material/sort/BUILD.bazel

@@ -67,7 +67,6 @@ ng_project(
         "index.ts",
         "public-api.ts",
         "sort.ts",
-        "sort-animations.ts",
         "sort-direction.ts",
         "sort-errors.ts",
         "sort-header.ts",

src/material/sort/public-api.ts

@@ -11,4 +11,3 @@ export * from './sort-direction';
 export * from './sort-header';
 export * from './sort-header-intl';
 export * from './sort';
-export * from './sort-animations';