Increase odds of transactions being included early by sending to multiple builders

[escottalexander]

It appears we can add a list of registered builders to our bundle to send to those builders:
https://docs.flashbots.net/flashbots-auction/advanced/multiplexing

Here is the list of currently supported builders and their names:
https://github.com/flashbots/dowg/blob/main/builder-registrations.json

I think originally I assumed that setting the builders restricted to just those builders but looking back at all my test transactions, 6 out of 8 have been built by Flashbots which seems odd considering when you look at the list of blocks that have been built it is very rare to see one built by Flashbots. Lots by beaverbuild and Titan Builder. Not conclusive but it shouldn't hurt to add the builders to request and see if that improves the speed at which bundles get included.