Remove cache for PYTHON_INCLUDE_DIRS

cmake/ThirdPartyPython.cmake

@@ -35,9 +35,6 @@ IF (NEKTAR_BUILD_PYTHON)
     FIND_PACKAGE(PythonInterp  ${PYTHONVER} REQUIRED)
     FIND_PACKAGE(PythonLibsNew ${PYTHONVER} REQUIRED)
 
-    # Save include dir in Cache for subsequent configures.
-    SET(PYTHON_INCLUDE_DIRS ${PYTHON_INCLUDE_DIRS} CACHE INTERNAL "" FORCE)
-
     # Include headers from root directory for config file.
 
     # Now try to find Boost::Python. For now we are relying entirely on