Some users of this library set `update_condition=0` on `upsert` for not updating anything on conflict.

The `upsert` documentation says:
> update_condition:
>   Only update if this SQL expression evaluates to true.

A value evaluating to Python `False` is ignored while the documentation says no update will be done.

[#186513018]

Some users of this library set `update_condition=0` on `upsert` for not updating anything on conflict.

The `upsert` documentation says:
> update_condition:
>   Only update if this SQL expression evaluates to true.

A value evaluating to Python `False` is ignored while the documentation says no update will be done.

[#186513018]

…newer

The following change broke the auto setup:
django/django@d3e746a

This breaks because the call to `pscygop2.extras.register_hstore` is now
conditional. Before, it would be called multiple times with
empty OIDS, when eventually our auto registration would kick
in and psycopg2 would fetch the OIDs itself.

…== ConflictAction.NOTHING` and rows parameter is iterator or generator

Most modern linters (like `ruff`) will complain about `meta.key` being a list, as it's a mutable class variable. Allowing a tuple here appears to work fine and removes the need to override linter rules for `meta.key`.

Co-authored-by: Hannes Engelhardt <[email protected]>