Update `matrix-bot-sdk` library to incorporate `device_keys` fix

[anoadragon453]

@Half-Shot noted that we're currently using an outdated fork of element-hq/matrix-bot-sdk. The latest version includes a fix for matrix-org/matrix-rust-sdk-crypto-nodejs#53.

As we don't use encryption as part of running FOSDEM, we don't enable any encryption features in the bot. However, @Half-Shot says it's possible that the bot will break once the associated validation on the Synapse side is re-enabled.

We should ensure to keep our libraries up to date regardless.

[Half-Shot]

I think it's very unlikely, but we can remove all doubt with a version bump 😁