Mui: restore removed default export

Author: garronej

src/mui/index.ts

@@ -1,2 +1,4 @@
 export * from "./mui";
+import { MuiDsfrThemeProvider } from "./mui";
 export { useIsGov } from "./useIsGov";
+export default MuiDsfrThemeProvider;

src/mui/mui.tsx

@@ -393,8 +393,6 @@ export function createMuiDsfrThemeProvider(params: {
 
 export const { MuiDsfrThemeProvider } = createMuiDsfrThemeProvider({});
 
-export default MuiDsfrThemeProvider;
-
 export function createDsfrCustomBrandingProvider(params: {
     createMuiTheme: (params: {
         isDark: boolean;