Go through sentry 2.0 migration guide

[wookie184]

We should make sure we aren't using any of the methods deprecated in this major release, in the migration guide (https://docs.sentry.io/platforms/python/migration/1.x-to-2.x) push_scope is mentioned as being deprecated but we still use it here: https://github.com/python-discord/sir-lancebot/blob/7bd936f50668791d404358bcd74fb82b6e6656f6/bot/exts/core/error_handler.py#L8

Originally posted by @wookie184 in https://github.com/python-discord/sir-lancebot/issues/1519#issuecomment-2096631253

[jb3]

If it helps at all, the only change required for this is to literally swap push_scope for new_scope:

python-discord/bot@5b209b1 (#3047)

Our usages of push_scope are innocuous enough that the slight changes in behaviour are null for us.