Upsert ON CONFLICT does not respect all_tenants?: true on identity.

[kernel-io]

Describe the bug
generated ON CONFLICT clause still includes multitenancy attribute even when the identity has all_tenants?: true set.

To Reproduce
When you have an identity with all_tenants?: true and you go to perform an upsert (while providing a tenant) - there will be an error from Postgrex

** (Postgrex.Error) ERROR 42P10 (invalid_column_reference) there is no unique or exclusion constraint matching the ON CONFLICT specification",

Expected behavior
the generated ON CONFLICT clause will not include the multitenancy attribute if the identity has all_tenants? set to true.

[zachdaniel]

@kernel-io would it be possible to provide a failing test illustrating this behavior? I will fix it, but I'm strapped on time and that would help me get to this sooner.

[kernel-io]

yup, I'll write a test over the weekend hopefully 👍🏾