Do not count number of library source folders

It's rather uninteresting noise.

Author: hasselmm

toolchain/arduino-cli-toolchain.cmake

@@ -711,8 +711,7 @@ function(__arduino_add_import_library NAME SOURCE_DIR) # [SOURCE_DIR...]
     __arduino_collect_source_files(_library_sources ${_library_directories}) # <----- collect the library's source files
 
     list(LENGTH _library_sources _source_file_count)
-    list(LENGTH _library_directories _source_dir_count)
-    message(STATUS "  ${_source_file_count} source files found for ${_target} in ${_source_dir_count} directories")
+    message(STATUS "  ${_source_file_count} source files found for ${_target}")
 
     list(JOIN _library_sources     "\"\n    \"" _quoted_library_sources) # <--------- prepare CMake to build out of tree
     list(JOIN _library_directories "\"\n    \"" _quoted_library_directories)