Consider using unfinalised but safe with ethereum light client instead of finalised

[womensrights]

To reduce the bridging time, we could use unfinalized but safe headers which would reduce the bridging time

[linear]

IBCSOL-229 Consider using unfinalised but safe with ethereum light client instead of finalised

[srdtrk]

Terminology nit. In the context of Ethereum L1, there is no safe header. We have finalized and attested headers. So the proposal here would be to use the attested headers