chore: reduce the default EVM gas limit

[rach-id]

Overview

Currently, relaying attestations takes around 550000 gas, and deploying the contracts around 1250000 gas. So, we can reduce the default gas limit to a more realistic value.

Checklist

• New and updated code has appropriate documentation
• New and updated code has new and/or updated testing
• Required CI checks are passing
• Visual proof for any user facing features like CLI or documentation updates
• Linked issues closed with keywords

[codecov-commenter]

Codecov Report

Merging #497 (e8aea19) into main (73b0565) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##             main     #497   +/-   ##
=======================================
  Coverage   25.37%   25.37%           
=======================================
  Files          29       29           
  Lines        2834     2834           
=======================================
  Hits          719      719           
  Misses       2029     2029           
  Partials       86       86           

Files	Coverage Δ
evm/evm_client.go	52.25% <ø> (ø)