Fix incorrect parameter name in date pickers custom components documentation from variant to pickerVariant

Problem

The documentation in docs/data/date-pickers/custom-components/custom-components.md shows an incorrect parameter name in the actionBar slotProps example. The example uses variant but the actual PickerOwnerState interface defines the property as pickerVariant.

Current (incorrect) documentation:

actionBar: ({ variant }) => ({
      actions: variant === 'desktop' ? [] : ['clear'],
    }),

Source: https://mui.com/x/react-date-pickers/custom-components/#component-props

Actual interface definition:

export interface PickerOwnerState {
  pickerVariant: PickerVariant;
  // ... other properties
}

Source: https://github.com/mui/mui-x/blob/master/packages/x-date-pickers/src/models/pickers.ts#L56

Solution

Update the documentation example to use the correct parameter name pickerVariant instead of variant.

Fixed documentation:

actionBar: ({ pickerVariant }) => ({
      actions: pickerVariant === 'desktop' ? [] : ['clear'],
    }),

Impact

This fix ensures developers using the slotProps API get the correct parameter name, preventing runtime/linter errors and improving developer experience.

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