Fee Recipient is not COINBASE

[sambacha]

Regarding

execution-apis/src/schemas/execute.yaml

Line 117 in e56d320

BlockOverrides:

this is incorrect.

COINBASE is an EVM Opcode, Fee Recipient is an out of protocol definition provided by the validator to block builder.

It can be the same, but not necessarily so (its the same if validator builds the block).

E.g. showing the registration process of setting fee recipient

PushProposerSettings calls the prepareBeaconProposer RPC to set the fee recipient and also the register validator API if using a custom builder.

https://github.com/prysmaticlabs/prysm/blob/96f1ebf7069d792e330d4cc618bdfea07180c03b/validator/client/validator.go#L1318

Builder sends a payment to fee recipient and can is COINBASE address.