op-node: generalize and improve alt-sync

batch-submitter: allow deposit only batches

op-proposer: add l2 block height metrics

maint: add Go to dependency list

Adds Go to the list of dependencies in the CONTRIBUTING guide.

chore(ctb): Bump `forge` & `forge-std`

config: set the L2 gaslimit to 30 million in config

contracts: add a method for building legacy bindings

feat(docs/op-stack): Show how to modify predeploys

fix(docs/op-stack): In superchain-diag, 2->3

feat(docs/op-stack): Add the getting in touch form

Co-authored-by: smartcontracts <kelvin@optimism.io>

Co-authored-by: smartcontracts <kelvin@optimism.io>

Co-authored-by: smartcontracts <kelvin@optimism.io>

As requested by Conduit.

Closing: DEVRL-780

fix(ci): run tests for common-ts

feat(ctb): Add constructor to init the SD implementation

op-chain-ops: Extract concurrent state iterator into util

Tests for common-ts were not being executed in CI because the command
being triggered was "yarn test:coverage" and this command was a noop for
common-ts. Also fixes a bug in the tests that wasn't caught by CI
because of this.

fix(sdk): automatically create std/ETH bridges