Update _document.tsx

[Arcktosh]

No need to import React, as it is not being used.
https://reactjs.org/blog/2020/09/22/introducing-the-new-jsx-transform.html

Signed-off-by: Ben Henning [email protected]

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

[mui-bot]

No bundle size changes

Generated by 🚫 dangerJS against 91c518e

[oliviertassinari]

@Arcktosh Interesting, thanks for raising. Now, reading https://reactjs.org/blog/2020/09/22/introducing-the-new-jsx-transform.html, this is not a one-line change. I would be in favor of:

1. Closing this PR. Why? While Next.js does it by default, it's not done by default until Babel v8. It's only done by default since TypeScript 4.1 but we support down to 3.5. Since there is no strong downsides to importing React, we can wait.
2. Opening a new issue to keep track of the opportunity, so we eventually do it, it sounds like a DX improvement.
   Maybe for MUI Core v6 [discussion] Preparing v6 #30660? :D
3. Once we resume the work on this, run the codemod to update all the codebase and update the eslint rules.