Pseudo finalization endpoint

[eserilev]

Issue Addressed

This is a backport of:

• Manual finalization endpoint #7059
• Add CI fixes to holesky-rescue #7071

For:

• Release v7.0.0-beta.clean #7039

Proposed Changes

Introduce a new lighthouse endpoint that allows a user to force a pseudo finalization. This migrates data to the freezer db and prunes sidechains which may help reduce disk space issues on non finalized networks like Holesky

We also ban peers that send us blocks that conflict with the manually finalized checkpoint.

There were some CI fixes in #7071 that I tried including here

Co-authored with: @jimmygchen @pawanjay176 @michaelsproul

[michaelsproul]

I've cherry-picked the split check fix from this PR:

• Fix descent from split check #7105

It would be awesome if we could add a unit test for manual finalization that shows it working correctly, and the node continuing to work after achieving real finalization.

I think we could add such a test in beacon_node/beacon_chain/tests.

[eserilev]

Added a test that

• creates an un-finalized chain
• pseudo finalizes + runs some checks
• extends & finalizes the chain + runs some checks

[michaelsproul]

Looks good

I will add one more test case using epochs_per_migration to delay the split update, as I think that case is also interesting.

[michaelsproul]

Regression test added and passing. Adding this to the queue.

[mergify]

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• ☑️ test-suite-success

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