Sc_Obligations: add support for the new User_Aspect_Definition pragma

(cherry picked from commit a523efc)

Author: pmderodat

tools/gnatcov/sc_obligations.ads

@@ -1013,6 +1013,7 @@ package SC_Obligations is
       Pragma_Unsuppress,
       Pragma_Unused,
       Pragma_Use_VADS_Size,
+      Pragma_User_Aspect_Definition,
       Pragma_Validity_Checks,
       Pragma_Volatile,
       Pragma_Volatile_Components,
@@ -1124,6 +1125,7 @@ package SC_Obligations is
           Pragma_Universal_Data => False,
           Pragma_Unsuppress => False,
           Pragma_Use_VADS_Size => False,
+          Pragma_User_Aspect_Definition => False,
           Pragma_Validity_Checks => False,
           Pragma_Warning_As_Error => False,
           Pragma_Warnings => False,