Remove the unused task_group include

GaudiHive/src/AvalancheSchedulerSvc.h

@@ -117,8 +117,7 @@ public:
   /// Constructor
   using extends::extends;
 
-  /// Destructor. Need to enforce noexcept specification as otherwise the noexcept(false) destructor of the
-  /// tbb::task_group member violates the contract
+  /// Destructor
   ~AvalancheSchedulerSvc() noexcept override {}
 
   /// Initialise

GaudiHive/src/ThreadPoolSvc.cpp

@@ -13,7 +13,6 @@
 #include "GaudiKernel/ConcurrencyFlags.h"
 #include "ThreadInitTask.h"
 
-#include "tbb/task_group.h"
 
 #include <chrono>
 #include <thread>