fix(material/core): remove deprecated factory functions

Removes factory functions that we had marked as deprecated for v21. These functions aren't necessary since we switched to standalone.

BREAKING CHANGE:
* `MAT_DATE_LOCAL_FACTORY` has been removed.

Author: crisbeto

goldens/material/core/index.api.md

@@ -154,9 +154,6 @@ export const MAT_DATE_FORMATS: InjectionToken<MatDateFormats>;
 // @public
 export const MAT_DATE_LOCALE: InjectionToken<{}>;
 
-// @public @deprecated
-export function MAT_DATE_LOCALE_FACTORY(): {};
-
 // @public (undocumented)
 export const MAT_NATIVE_DATE_FORMATS: MatDateFormats;
 

src/material/core/datetime/date-adapter.ts

@@ -12,18 +12,9 @@ import {Observable, Subject} from 'rxjs';
 /** InjectionToken for datepicker that can be used to override default locale code. */
 export const MAT_DATE_LOCALE = new InjectionToken<{}>('MAT_DATE_LOCALE', {
   providedIn: 'root',
-  factory: MAT_DATE_LOCALE_FACTORY,
+  factory: () => inject(LOCALE_ID),
 });
 
-/**
- * @docs-private
- * @deprecated No longer used, will be removed.
- * @breaking-change 21.0.0
- */
-export function MAT_DATE_LOCALE_FACTORY(): {} {
-  return inject(LOCALE_ID);
-}
-
 const NOT_IMPLEMENTED = 'Method not implemented';
 
 /** Adapts type `D` to be usable as a date by cdk-based components that work with dates. */