[PyROOT] Destroy STL string objects in StringExecutor

::operator delete only frees the memory that was previously allocated in
Cppyy::CallO, but does not call the destructor of the std::string. Make sure
that is done using keyword delete.

Author: vepadulano

bindings/pyroot/cppyy/CPyCppyy/src/Executors.cxx

@@ -566,7 +566,7 @@ PyObject* CPyCppyy::STLStringExecutor::Execute(
 
     PyObject* pyresult =
         CPyCppyy_PyText_FromStringAndSize(result->c_str(), result->size());
-    ::operator delete(result); // calls Cppyy::CallO which calls ::operator new
+    delete result; // Cppyy::CallO allocates and constructs a string, so it must be properly destroyed
 
     return pyresult;
 }
@@ -584,7 +584,7 @@ PyObject* CPyCppyy::STLWStringExecutor::Execute(
     }
 
     PyObject* pyresult = PyUnicode_FromWideChar(result->c_str(), result->size());
-    ::operator delete(result); // calls Cppyy::CallO which calls ::operator new
+    delete result; // Cppyy::CallO allocates and constructs a string, so it must be properly destroyed
 
     return pyresult;
 }