Fix DartDoc section in Diagnostics server for LSP

Change-Id: I8bb40a08b7b6aa53c962bc5a86eb3e68a330a87c
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/102620
Reviewed-by: Brian Wilkerson <[email protected]>
Commit-Queue: Danny Tuppeny <[email protected]>

Author: DanTup

pkg/analysis_server/lib/src/status/diagnostics.dart

@@ -551,9 +551,9 @@ class ContextsPage extends DiagnosticPageWithNav {
     }
 
     h3('Dartdoc template info');
-    DartdocDirectiveInfo info = (server as AnalysisServer).declarationsTracker
-        ?.getContext(driver.analysisContext)
-        ?.dartdocDirectiveInfo ??
+    DartdocDirectiveInfo info = server.declarationsTracker
+            ?.getContext(driver.analysisContext)
+            ?.dartdocDirectiveInfo ??
         new DartdocDirectiveInfo();
     writeMap(info.templateMap);
   }