COMP: Do not use quotes in ExternalProject ITK_WRAP_IMAGE_DIMS

Causes issues with CMake 3.20.

Author: thewtex

CMakeLists.txt

@@ -226,7 +226,7 @@ if(ITKPythonPackage_SUPERBUILD)
         -DITK_WRAP_PYTHON:BOOL=ON
         -DITK_WRAP_unsigned_short:BOOL=ON
         -DITK_WRAP_double:BOOL=ON
-        -DITK_WRAP_IMAGE_DIMS:STRING="2;3;4"
+        -DITK_WRAP_IMAGE_DIMS:STRING=2;3;4
         -DITK_WRAP_DOC:BOOL=ON
         -DDOXYGEN_EXECUTABLE:FILEPATH=${DOXYGEN_EXECUTABLE}
         -DPython3_INCLUDE_DIR:PATH=${Python3_INCLUDE_DIR}