(DateInput, DatePicker): remove unnecessary a11y attributes

Author: msmx-mnakagawa

src/scripts/DateInput.tsx

@@ -358,7 +358,6 @@ export const DateInput = createFC<DateInputProps, { isFormElement: boolean }>(
               icon='event'
               disabled={props.disabled}
               className='slds-input__icon slds-input__icon_right'
-              alt='Select a date'
               tabIndex={-1}
               onClick={props.disabled ? undefined : onDateIconClick}
               onBlur={onInputBlur}

src/scripts/Datepicker.tsx

@@ -496,7 +496,6 @@ export const Datepicker: FC<DatepickerProps> = (props) => {
       tabIndex={-1}
       role='dialog'
       aria-hidden={false}
-      aria-label={`Date picker: ${dayjs.monthsShort()[cal.month]}`}
       onBlur={onBlur}
       onKeyDown={onKeyDown}
     >