fix(contracts): Resolve dependency issues and improve cert verifier router deployment workflow

[Mc01]

Why are these changes needed?

Fixes configuration issues and improves the cert verifier router deployment scripts encountered when deploying from the v2.6.0 tag.

Changes

• Dependency Configuration

  • Update eigenlayer-middleware submodule to use m2-mainnet branch instead of m2-mainnet-fixes
  • Add foundry.lock to track dependency versions explicitly
  • Fix OpenZeppelin remappings to use lib/ instead of node_modules/

• Deployment Script Improvements

  • Reorganize imports in CertVerifierRouterDeployer.s.sol for better readability
  • Simplify output path structure (remove unnecessary chainid subdirectory -> similarly as done in CertVerifierDeployer)
  • Improve code formatting and comments

• Git Ignore & Directory Structure

  • Add .gitignore rules for deployment artifacts (config/input/output files)
  • Add .gitkeep in output directories (scripts were breaking with directory not exists)
  • Ensure deployment output directories are tracked properly

Motivation

These changes enable successful deployment of the cert verifier router by resolving dependency mismatches and streamlining the deployment workflow.

Checks

• I've run forge test & everything works. Changes do not affect other files than deployment scripts

[Mc01]

Would appreciate feedback if PR should be created against the master (or any other branch) as the base branch