message: Fix test matrix forcing basix lib to be loaded
diff: #include <ringmesh/ringmesh_tests_config.h>
  -#include <geogram/basic/string.h>
  #include <ringmesh/basic/logger.h>
  #include <ringmesh/basic/matrix.h>
  +#include <ringmesh/basic/plugin_manager.h>
  /*!
  * @author Benjamin Chauvin
  @@ -146,6 +146,7 @@ int main()
  try
  {
  + PluginManager::load_plugin( "RINGMesh_basic" );
  Logger::out( "TEST", "Test Matrix" );
  run_tests();
  }
  