Keep up-to-date with pyo3 releases. This bump enables Python 3.13
support and resolves deprecations.

Links for quick reference:
https://github.com/PyO3/pyo3/releases
https://github.com/davidhewitt/pythonize/releases
https://github.com/vorner/pyo3-log

Add `event.internal_metadata.instance_name` (the worker instance that persisted the event) to go alongside the existing `event.internal_metadata.stream_ordering`.

`instance_name` is useful to properly compare and query for events with a token since you need to compare both the `stream_ordering` and `instance_name` against the vector clock/`instance_map` in the `RoomStreamToken`.

This is pre-requisite work and may be used in https://github.com/element-hq/synapse/pull/17293

Adding `event.internal_metadata.instance_name` was first mentioned in the initial Sliding Sync PR while pairing with @erikjohnston, see https://github.com/element-hq/synapse/pull/17187/commits/09609cb0dbca3a4cfd9fbf90cc962e765ec469c0#diff-5cd773fb307aa754bd3948871ba118b1ef0303f4d72d42a2d21e38242bf4e096R405-R410

This version change requires a migration to a new API. See
https://pyo3.rs/v0.21.2/migration#from-020-to-021

This will fix the annoying warnings added when using the recent rust
nightly:

> warning: non-local `impl` definition, they should be avoided as they
go against expectation

Co-authored-by: Andrew Morgan <1342360+anoadragon453@users.noreply.github.com>

There are a couple of things we need to be careful of here:

1. The current python code does no validation when loading from the DB,
so we need to be careful to ignore such errors (at least on jki.re there
are some old events with internal metadata fields of the wrong type).
2. We want to be memory efficient, as we often have many hundreds of
thousands of events in the cache at a time.

---------

Co-authored-by: Quentin Gliech <quenting@element.io>