don't use hooks conditionally in docs (#7473)

Author: nathanpower

packages/react-aria-components/docs/Calendar.mdx

@@ -840,7 +840,8 @@ function CalendarValue() {
   let state = React.useContext(CalendarStateContext)!;
   /*- end highlight -*/
   let date = state.value?.toDate(getLocalTimeZone());
-  let formatted = date ? useDateFormatter().format(date) : 'None';
+  let {format} = useDateFormatter();
+  let formatted = date ? format(date) : 'None';
   return <small>Selected date: {formatted}</small>;
 }
 

packages/react-aria-components/docs/advanced.mdx

@@ -245,7 +245,8 @@ function CalendarValue() {
   let state = React.useContext(CalendarStateContext)!;
   /*- end highlight -*/
   let date = state.value?.toDate(getLocalTimeZone());
-  let formatted = date ? useDateFormatter().format(date) : 'None';
+  let {format} = useDateFormatter();
+  let formatted = date ? format(date) : 'None';
   return `Selected date: ${formatted}`;
 }
 ```