[material-ui] Use interface instead of type for props (#41500)

packages/mui-base/src/Unstable_Popup/Popup.tsx

@@ -16,10 +16,10 @@ import {
 } from '@mui/utils';
 import { unstable_composeClasses as composeClasses } from '../composeClasses';
 import { Portal } from '../Portal';
-import { useSlotProps, WithOptionalOwnerState } from '../utils';
+import { useSlotProps, WithOptionalOwnerState, PolymorphicComponent } from '../utils';
 import { useClassNamesOverride } from '../utils/ClassNameConfigurator';
 import { getPopupUtilityClass } from './popupClasses';
-import { PopupOwnerState, PopupProps, PopupRootSlotProps } from './Popup.types';
+import { PopupOwnerState, PopupProps, PopupRootSlotProps, PopupTypeMap } from './Popup.types';
 import { useTransitionTrigger, TransitionContext } from '../useTransition';
 import { PopupContext, PopupContextValue } from './PopupContext';
 
@@ -154,7 +154,7 @@ const Popup = React.forwardRef(function Popup<RootComponentType extends React.El
       </PopupContext.Provider>
     </Portal>
   );
-});
+}) as PolymorphicComponent<PopupTypeMap>;
 
 Popup.propTypes /* remove-proptypes */ = {
   // ┌────────────────────────────── Warning ──────────────────────────────┐

packages/mui-material/src/Popper/Popper.tsx

@@ -8,7 +8,7 @@ import PropTypes from 'prop-types';
 import * as React from 'react';
 import { styled, Theme, useThemeProps } from '../styles';
 
-export type PopperProps = Omit<BasePopperProps, 'direction'> & {
+export interface PopperProps extends Omit<BasePopperProps, 'direction'> {
   /**
    * The component used for the root node.
    * Either a string to use a HTML element or a component.
@@ -31,7 +31,7 @@ export type PopperProps = Omit<BasePopperProps, 'direction'> & {
    * The system prop that allows defining system overrides as well as additional CSS styles.
    */
   sx?: SxProps<Theme>;
-};
+}
 
 const PopperRoot = styled(BasePopper, {
   name: 'MuiPopper',