Faheel/add minimal spec

[faheelsattar]

📝 Summary

Adds support for dyn ssz in mev-boost which allows spinning devnets with minimal specs

⛱ Motivation and Context

Faster iterative testing on devnets

📚 References

https://github.com/flashbots/mev-boost/issues/800

✅ I have run these commands

• [x] make lint
• [x] make test-race
• [x] go mod tidy