Do not look for macros in hidden folders (#14374)

Author: ktf

cmake/O2GetListOfMacros.cmake

@@ -18,7 +18,7 @@ include_guard()
 function(o2_get_list_of_macros dir varname)
   file(GLOB_RECURSE listOfMacros RELATIVE ${CMAKE_SOURCE_DIR} ${dir}/*.C)
   # Case sensitive filtering of .C files (to avoid .c files on Mac)
-  list(FILTER listOfMacros INCLUDE REGEX "^.*\\.C$")
+  list(FILTER listOfMacros INCLUDE REGEX "^[^.].*\\.C$")
   # Remove macros that were copied to the build directory, to deal with
   # the (non-recommended-but-can-happen) case where the build directory
   # is a subdirectory of the source dir