* ci: move `op-bindings` check to own job

This should speed up the CI so that the check for the
`op-bindings` runs in parallel with the `contracts-bedrock`
tests. This step is often very slow compared to others and
I often find myself waiting on it.

* contracts-bedrock: update readme

Delete some dead info
Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>