[FIX] base: return super().unlink() for ir.ui.view.unlink()

Commit bca2926b introduced a fix for
ir.ui.view unlinks during uninstall but forgot to return the result of
the super() call to unlink which broke behaviour downstream.

This commit restores the proper behavior of returning the result of the
call to super.

Closes #52364

closes odoo/odoo#52435

X-original-commit: a3d91cc8
Signed-off-by: Adrian Torres (adt) <adt@odoo.com>