Add missing dev dependencies to base/next

[Janpot]

Discovered this while trying a few things with rollup while investigating #30510 and #30200
@mui/material is being used in the tests of these packages.

[mui-pr-bot]

No bundle size changes

Generated by 🚫 dangerJS against 2540dec

[siriwatknp]

This looks strange to me because mui-base should not use anything from the design system package (mui-material). cc @michaldudak

[Janpot]

The package itself doesn't use it, only some of its tests do. I can imagine there to be legitimate use cases for that. e.g. to verify that both packages integrate correctly. Point is, that if it's used, it's best to declare it in the package.json to avoid confusing any tools that try to statically analyse dependencies.

[michaldudak]

Actually, the correct solution here would be to refactor the tests not to use @mui/material. The Base package should be standalone as much as possible. The integration testing is done in the material-next package.

I suggest closing this PR without merging. I'll create a follow-up to clean the tests.

[Janpot]

@michaldudak Thanks for looking into this. One thing to be aware of, in @mui/material-next it's not the tests, it's the typings that import @mui/material.