fix(material/datepicker): remove deprecated animation definitions

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

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

Author: crisbeto

goldens/material/datepicker/index.api.md

@@ -330,12 +330,6 @@ export class MatDatepickerActions implements AfterViewInit, OnDestroy {
     static ɵfac: i0.ɵɵFactoryDeclaration<MatDatepickerActions, never>;
 }
 
-// @public @deprecated
-export const matDatepickerAnimations: {
-    readonly transformPanel: any;
-    readonly fadeInCalendar: any;
-};
-
 // @public
 export class MatDatepickerApply {
     constructor(...args: unknown[]);

src/material/datepicker/BUILD.bazel

@@ -132,7 +132,6 @@ ng_project(
         "date-selection-model.ts",
         "datepicker.ts",
         "datepicker-actions.ts",
-        "datepicker-animations.ts",
         "datepicker-base.ts",
         "datepicker-errors.ts",
         "datepicker-input.ts",

src/material/datepicker/datepicker-animations.ts

@@ -15,7 +15,6 @@ export {
   MatDateRangeSelectionStrategy,
   DefaultMatCalendarRangeStrategy,
 } from './date-range-selection-strategy';
-export * from './datepicker-animations';
 export {
   MAT_DATEPICKER_SCROLL_STRATEGY,
   MAT_DATEPICKER_SCROLL_STRATEGY_FACTORY,