Update getting started page

layouts/shortcodes/pages/getting-started/landing-page.html

 {{ $bugzillaLink := "https://bugs.eclipse.org/bugs/enter_bug.cgi?product=EPP" }}
 {{ $installButtonImageUrl := "https://download.eclipse.org/eclipse.org-common/themes/solstice/public/images/components/drag-drop/installbutton.png" }}
-{{ $versionName := "2023-03" }}
-{{ $platformVersion := "4.27" }}
+{{ $versionName := "2023-06" }}
+{{ $platformVersion := "4.28" }}
 
 <div class="timeline">
   <div class="row">