Remove all prod eth1 related code

[pawanjay176]

Issue Addressed

N/A

Proposed Changes

After the electra fork which includes EIP 6110, the beacon node no longer needs the eth1 bridging mechanism to include new deposits as they are provided by the EL as a deposit_request. So after electra + a transition period where the finalized bridge deposits pre-fork are included through the old mechanism, we no longer need the elaborate machinery we had to get deposit contract data from the execution layer.

Since holesky has already forked to electra and completed the transition period, this PR basically checks to see if removing all the eth1 related logic leads to any surprises.

[mergify[bot]]

This pull request has merge conflicts. Could you please resolve them @pawanjay176? 🙏

[michaelsproul]

Hey @pawanjay176 I am keen to get this merged, would it help if I resolved merge conflicts and rolled this out on a few more nodes?

[pawanjay176]

Resolved the conflicts. Would be awesome if we can roll this on some nodes with validators and check that block production works without any hitch 🙏

[michaelsproul]

I think the failing tests are fine as well, just need to update some expected state roots due to the changes to the eth1 data voting (not significant for what those tests are testing anyway).

[pawanjay176]

Thanks for reviewing and fixing up everything Michael ❤️