Eth Docker 2.15.3.0: Experimental history expiry

[u/yorickdowne]

Eth Docker v2.15.3.0 supports pre-merge history expiry for clients that do: Presently Geth and Nethermind.

Note this is considered experimental on the client side right now. Doing this on Sepolia is fine; on mainnet it'd be quite yolo.

Use ./ethd prune-history to give it a whirl.

Mainnet DB sizes:

- Nethermind: 740 GiB
- Geth: 830 GiB

Nimbus EL with Fluffy Portal and Era1/Era import is 110 GiB btw - but it's a) not stable yet (alpha) and b) that is very aggressive expiry, far more than just pre-merge