Arbitrum Token Bridge v1.2.4

What's Changed

This release does not change any contracts. The main change is bumping arbitrum-sdk to v4.

• nits on README by @0xallan in #104
• Stable foundry by @godzillaba in #106
• Use template repo's signature and storage test scripts by @godzillaba in #107
• Bump sdk by @godzillaba in #105

New Contributors

• @0xallan made their first contribution in #104

Full Changelog: v1.2.3...v1.2.4