Using the lib as online stayer only - disable guild subscriptions

[sla-te]

Basically the title says it all, it seems passing

max_messages=None,
chunk_guilds_at_startup=False,
guild_subscriptions=False,

does not do the trick anymore.

[dolfies]

max_messages=None,
chunk_guilds_at_startup=False,
guild_subscription_options=GuildSubscriptionOptions.off()

This should get rid of most of the overhead.
Next release I'm probably adding guild_subscriptions back in, to disable "requesting" guilds (subscribing to events on large guilds).

[sla-te]

christ guild_subscription_options=GuildSubscriptionOptions.off() just made the script 10x as fast ^^ tysm