fix: Zero out salts to get Docker Compose helper working

[sds]

Motivation

When using this repo for local development, the use of salts seems to interfere with running the l2-deployer container.

Change Summary

Fix by zeroing out the hashes. @horsefacts: is there a way we can override these salts locally via environment variables? (just in the docker-compose.yml so this still works in local dev)

While here, add some tests that confirm the L2 contracts are deployed correctly.

Merge Checklist

• [x] The PR title adheres to the conventional commits standard
• [x] The PR has been tagged with change type label(s) (i.e. documentation, feature, bugfix, or chore)
• [x] The PR's changes adhere to all the requirements in the contribution guidelines
• [x] All commits have been signed

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PR-Codex overview

The following files were skipped due to too many changes: .env.example, script/DeployL2.s.sol

✨ Ask PR-Codex anything about this PR by commenting with /codex {your question}

[github-actions[bot]]

Coverage after merging sds/fix-docker-compose into main will be

98.66%

Coverage Report

File	Stmts	Branches	Funcs	Lines	Uncovered Lines
src
Bundler.sol	100%	100%	100%	100%
FnameResolver.sol	100%	100%	100%	100%
IdRegistry.sol	100%	100%	100%	100%
KeyRegistry.sol	100%	100%	100%	100%
RecoveryProxy.sol	100%	100%	100%	100%
StorageRegistry.sol	100%	100%	100%	100%
src/lib
EIP712.sol	50%	100%	50%	50%	19
Signatures.sol	100%	100%	100%	100%
TransferHelper.sol	0%	0%	0%	0%	12, 17, 20, 20, 20
TrustedCaller.sol	100%	100%	100%	100%
src/validators
SignedKeyRequestValidator.sol	100%	100%	100%	100%