chore(docs): use static values in demos

Author: Mash707

packages/react-core/src/components/Timestamp/examples/TimestampDefaultTooltip.tsx

@@ -1,7 +1,7 @@
 import { Timestamp, TimestampTooltipVariant } from '@patternfly/react-core';
 
 export const TimestampDefaultTooltip: React.FunctionComponent = () => {
-  const currentDate = new Date();
+  const currentDate = new Date('2025-04-21T14:30:00');
 
   return (
     <>