mui/mui-x v5.6.1 on GitHub

We'd like to offer a big thanks to the 8 contributors who made this release possible. Here are some highlights ✨:

[DataGrid] Allow to add margins or borders between rows (#3848) @m4theushw
```
<DataGrid getRowSpacing={() => ({ top: 10, bottom: 10 })} />
```
Check the documentation for more information.

[DataGrid] Display column's filter icon if a filter is applied (#4120) @DanailH
[DataGrid] Do not loop through rows to compute top level rows count when the tree is flat (#4081) @flaviendelangle
[DataGrid] Rename API method (#4148) @m4theushw
[DataGrid] Support extending built-in column types (#4114) @cherniavskii
[DataGridPro] Re-export the components removed by mistake during bundle split (#4134) @flaviendelangle

[docs] Fix links to prevent duplicate search result (#4130) @siriwatknp
[docs] Fix outdated links to localeTextConstants.ts (#4080) @patilvishal755
[docs] Neglect e2e tests related to search (#4118) @siriwatknp
[docs] Use regex instead of specific url in e2e-website-tests (#4121) @siriwatknp

[core] Enforce noImplicitAny (#4084) @cherniavskii
[core] Improve the Pro support issue template (#4082) @oliviertassinari
[core] Initialize remaining states before feature hooks (#4036) @m4theushw
[core] Merge page and pageSize state initializer into a single pagination state initializer (#4087) @flaviendelangle
[core] Prepare yarn docs:api:build scripts for multi packages support (#4111) @flaviendelangle
[core] Upgrade @mui/monorepo (#4149) @cherniavskii
[core] Use buildWarning and wrapWithWarningOnCall for deprecated methods and wrong usages (#4056) @flaviendelangle
[test] Make focus state out-of-sync warning opt-in (#4129) @m4theushw
[test] Only test custom input keyboard event in edit mode (#4075) @alexfauquette