Fix #119554: Remove links to and from unsupported socket types.

types and avoid crashing with unknown default_value data. However, this
did not update link pointers (which haven't been read at that point),
so the tree can end up with dangling pointers.

To fix this, removal of unsupported sockets is moved further back to a
point where links have been read and can be fixed accordingly.

@@ -716,1 +724,4 @@
     }
+
+    BLI_remlink(sockets, sock);
+    MEM_freeN(sock->runtime);