Fix #121075: Outliner Ctrl-clicking to toggle selection has speed limit

There are a couple of keymap entries for `OUTLINER_OT_item_activate` in
our keymap. One of them has Ctrl+dblclick as a binding to trigger
recursion, but that one exits early when not dblclicking on the icon.
(introduced in 796577d76e)

It does not exit in a way that the non-dblclick variant can run, for
that we need to exit with OPERATOR_PASS_THROUGH, so that the "other"
operator can run as well.

Pull Request: https://projects.blender.org/blender/blender/pulls/121130

source/blender/editors/space_outliner/outliner_select.cc

@@ -1839,7 +1839,7 @@ static int outliner_item_do_activate_from_cursor(bContext *C,
         }
         else {
           /* Double-clicked, but it wasn't on the icon. */
-          return OPERATOR_CANCELLED;
+          return OPERATOR_CANCELLED | OPERATOR_PASS_THROUGH;
         }
       }
       else {