TaskTree: Prepare for de-utils-ization - part 3

Rename QTC_* macros into TASKING_*.

Change-Id: I809ebf678f20df612a3211c38ebbfe6d4bf6492d
Reviewed-by: hjk <hjk@qt.io>
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>

src/plugins/languageclient/currentdocumentsymbolsrequest.h

@@ -48,5 +48,5 @@ public:
 
 } // namespace LanguageClient
 
-QTC_DECLARE_CUSTOM_TASK(CurrentDocumentSymbolsRequestTask,
+TASKING_DECLARE_TASK(CurrentDocumentSymbolsRequestTask,
                         LanguageClient::CurrentDocumentSymbolsRequestTaskAdapter);