feat: add onGenerateMock transformer callback (#15429)

packages/jest-environment/src/index.ts

@@ -207,18 +207,6 @@ export interface Jest {
     moduleFactory?: () => T,
     options?: {virtual?: boolean},
   ): Jest;
-  /**
-   * Registers a callback function that is invoked whenever a mock is generated for a module.
-   * This callback is passed the module name and the newly created mock object, and must return
-   * the (potentially modified) mock object.
-   *
-   * If multiple callbacks are registered, they will be called in the order they were added.
-   * Each callback receives the result of the previous callback as the `moduleMock` parameter,
-   * making it possible to apply sequential transformations.
-   *
-   * @param cb
-   */
-  onGenerateMock<T>(cb: (moduleName: string, moduleMock: T) => T): Jest;
   /**
    * Mocks a module with the provided module factory when it is being imported.
    */