[TypeScript] Fix theme options components types to use Theme

[siriwatknp]

Issue

Currently, you can't use the custom node that augment from the theme in components style overrides:

import * as React from 'react';
import { createTheme, styled } from '@mui/material/styles';
import Box from '@mui/material/Box';

interface CustomNode {
  background: string;
  color: string;
}

declare module '@mui/material/styles' {
  interface ThemeOptions {
    customNode: CustomNode;
  }

  interface Theme {
    customNode: CustomNode;
  }
}

const customTheme = createTheme({
  customNode: {
    background: '#000',
    color: '#fff',
  },
  components: {
    MuiAppBar: {
      stylesOverrides: {
        root: ({ theme }) => ({
          // @ts-expect-error: this should work!
          backgroundColor: theme.customNode.background,
        })
      }
    }
  }
});

• I have followed (at least) the PR section of the contributing guide.

[mui-bot]

No bundle size changes

Generated by 🚫 dangerJS against 9c5d69a

[mnajdova]

Nice catch