UseSWIG: Remove duplicate include dirs (#14520)

Shorten the swig command line.

Modules/UseSWIG.cmake

@@ -159,6 +159,7 @@ macro(SWIG_ADD_SOURCE_TO_MODULE name outfiles infile)
   #message("Full path to source file: ${swig_source_file_fullname}")
   #message("Full path to the output file: ${swig_generated_file_fullname}")
   get_directory_property(cmake_include_directories INCLUDE_DIRECTORIES)
+  list(REMOVE_DUPLICATES cmake_include_directories)
   set(swig_include_dirs)
   foreach(it ${cmake_include_directories})
     set(swig_include_dirs ${swig_include_dirs} "-I${it}")