There is now a new config flag for reading the L2Addresses
from disk. Note that the name L2Addresses should probably be
changed or migrated into the `DeployConfig` because now we
have overlapping sources of config.

There are deployment deps that would also need to be changed, so
doing the config change would require PRs across multiple repos.

The `sdk` tasks also consume a JSON file with addresses and this JSON
is different than that JSON which is not ideal.