[FIX] cetmix_tower_jet_isolation: expose uninstall_hook at module root level

Odoo resolves the hook with getattr(py_module, 'uninstall_hook'), so the
function must be a direct attribute of the package, not just a submodule.
Replace 'from . import hooks' with 'from .hooks import uninstall_hook'.

Author: marionumza

cetmix_tower_jet_isolation/__init__.py

@@ -1 +1,2 @@
-from . import hooks, models, wizards
+from . import models, wizards
+from .hooks import uninstall_hook