STYLE: Remove obsolete variable passed to inner build

This commit is a follow up of 35940011 (ENH: Update imstkSolveDependencies
module based on commontk/Artichoke@4176c39f9) where the variable should
have been originally removed.

CMake/External/CMakeLists.txt

@@ -96,7 +96,6 @@ ExternalProject_Add( ${PROJECT_NAME}
   DOWNLOAD_COMMAND ""
   SOURCE_DIR ${${PROJECT_NAME}_SOURCE_DIR}
   BINARY_DIR ${CMAKE_BINARY_DIR}/Innerbuild
-  ${COMMON_CMAKE_EP_ARGS}
   CMAKE_ARGS
     -D${PROJECT_NAME}_SUPERBUILD:BOOL=OFF
     -D${PROJECT_NAME}_BUILD_EXAMPLES:BOOL=${${PROJECT_NAME}_BUILD_EXAMPLES}