When using the Form the TimePicker is reported as valid even when the form field is required

[agubler]

Bug

When using the form widget and configuring a field to be "required" it should the whole form should only be valid once the input has been populated. The TimePicker reports as valid and therefore the forms valid state is set to true even though the required form as not been populated.

Codesandbox example: https://codesandbox.io/s/practical-solomon-wdysh?file=/src/main.tsx