chore: update fork diff base commit to v1.11.1
Update the base hash in fork.yaml to bef3d7b4d1 which is the upstream
paradigmxyz/reth commit corresponding to the v1.11.1 release (the parent
of the merge commit 515163491c).
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>