Add CodSpeed performance benchmarking integration

[codspeed-hq]

Summary

This PR integrates CodSpeed continuous performance testing into the dank_mids repository to track and monitor performance regressions across the codebase.

Changes include:

• Added pytest-codspeed as a dev dependency for performance benchmarking
• Created comprehensive benchmark suite in tests/benchmarks/ covering:
  • Multicall batching performance across single and multiple blocks
  • Various eth_* RPC method performance (getBalance, getCode, etc.)
  • Contract call performance benchmarks
• Added GitHub Actions workflow (.github/workflows/codspeed.yaml) with:
  • Simulation mode for consistent, hardware-agnostic measurements
  • OIDC authentication for secure, tokenless uploads
  • Proper Python and Poetry setup matching existing CI patterns
  • Integration with existing environment configuration (brownie networks, secrets)
• Added CodSpeed badge to README for visibility into performance trends

Test Plan

• Verify the CodSpeed workflow runs successfully on this PR
• Confirm benchmarks execute without errors
• Check that the CodSpeed installation comment appears on the PR
• Validate that performance data is uploaded and visible on the CodSpeed dashboard

Next Steps

After merging:

1. Monitor the CodSpeed dashboard at https://codspeed.io/BobTheBuidler/dank_mids
2. Review performance trends and establish baseline metrics
3. Set up performance checks to catch regressions in future PRs
4. Consider expanding the benchmark suite to cover additional critical paths

https://codspeed.io/BobTheBuidler/dank_mids?utm_source=badge