Merge branch 'GSF_MaterialEffectsMemoryLeak' into 'master'

Remove memory leak in MultiStateMaterialEffects

See merge request atlas/athena!15049

Tracking/TrkFitter/TrkGaussianSumFilter/TrkGaussianSumFilter/IMultiStateMaterialEffects.h

@@ -45,6 +45,7 @@ class IMultiStateMaterialEffects : virtual public IAlgTool{
     std::vector<double> weights;
     std::vector<double> deltaPs;
     std::vector<const AmgSymMatrix(5)*> deltaCovariances;
+    ~Cache(){ reset(); };
     void reset();   
   };