Closes #2328

This PR updates the peerDependencies of @jsonforms/material-renderers to allow for either v6 or v7 of @mui/x-date-pickers. I went through the v6 to v7 migration guide and didn't see any breaking changes that require a code change in @jsonforms/material-renderers. I also tried running the pickers codemod to see if it changes anything, but it didn't. I also checked the material-renderers Dates examples and confirmed they still work.

There is mention of updating @mui/material, but the examples seem to work without it. I was trying to better understand why the need for the update (mui/mui-x#12516) and it seemed like it was for a very specific use case (mui/mui-x#12248) that I don't think requires a corresponding peer dependency bump in @jsonforms/material-renderers, but happy to do so if you prefer.

In other words, think the material-renderers (as it's currently implemented) can support both @mui/x-date-pickers 6 and 7, but this would also mean that any future changes made in the control components would need to be tested against both versions, at least until the next major release of jsonforms where v6 support could be dropped.