Pass right day to isDateDisabled to avoid being able to select disabled days

[byanes]

This PR fixes an issue that allows selecting the 1st day of the following month when it has been disabled with a maxDate. This only happens when the current month is 31 days long and maxDate is set to the last day of the month.

Example:

<Datepicker
  value={{ startDate: null, endDate: null }}
  minDate={new Date('2023-08-01')}
  maxDate={new Date('2023-08-31')}
  useRange={false}
  asSingle={true}           
 />

This allows selecting September 1st when clicking on it from August's view:

[onesine]

Hi @byanes 👋

Sorry for the delay.

Thanks for this PR.