fix(kona-derive): Remove SignedRecoverable Shim

[refcell]

Description

Previously, building the kona-derive crate would fail with --no-default-features since the tx envelope's public key recovery method is only available when the k256 feature is enabled on alloy consensus.

This removes the SignedRecoverable trait shim and requires that k256 is enabled.

We will need to refactor kona-derive sources to be abstract over the signer recovery method so we're not locked into k256.

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 50.00000% with 1 line in your changes missing coverage. Please review.

Project coverage is 77.8%. Comparing base (5c30c4c) to head (4ea00d4).
Report is 1 commits behind head on main.

Files	Patch %	Lines
crates/derive/src/sources/blobs.rs	0.0%	1 Missing ⚠️

Additional details and impacted files

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.