add find_package for taskflow in sofa.helper cmake config

Author: olivier-roussel

Sofa/framework/Helper/Sofa.HelperConfig.cmake.in

@@ -9,6 +9,10 @@ sofa_find_package(Sofa.Topology QUIET REQUIRED)
 
 sofa_find_package(Eigen3 QUIET REQUIRED)
 
+if(NOT TARGET Taskflow::Taskflow)
+    sofa_find_package(Taskflow QUIET REQUIRED)
+endif()
+
 if(NOT TARGET @PROJECT_NAME@)
     include("${CMAKE_CURRENT_LIST_DIR}/@PROJECT_NAME@Targets.cmake")
 endif()