Migrate benchmark workflow from BenchmarkCI to AirspeedVelocity

[Krastanov-agent]

Summary

Migrates the benchmark workflow from manual BenchmarkCI implementation to the modern AirspeedVelocity action.

Changes

• Replaces 50+ line manual workflow with 3-line action
• Uses MilesCranmer/AirspeedVelocity.jl@action-v1
• Maintains same functionality: benchmark PRs and post results as comments

Benefits

✅ Much simpler - Reduces workflow from 50+ lines to just 3 lines
✅ Easier to maintain - No manual artifact handling or complex scripts
✅ Consistent - Matches other repos in the organization
✅ Modern - Uses the recommended Julia benchmarking action
✅ Same functionality - Automatic PR comments with benchmark comparisons

Migration Details

Before (BenchmarkCI):

• Manual setup of Julia, dependencies, and BenchmarkCI
• Custom scripts to run benchmarks and format output
• Manual artifact upload/download
• Requires maintenance of custom workflow logic

After (AirspeedVelocity):

- uses: MilesCranmer/AirspeedVelocity.jl@action-v1
  with:
    julia-version: '1'
    tune: 'false'

The action handles everything automatically:

• Checks out both base and PR branches
• Runs benchmark suite on both
• Compares results
• Posts formatted comment to PR

Test Plan

• Verify benchmark.yml has been replaced with AirspeedVelocity action
• Create a test PR to verify benchmarks run correctly
• Confirm benchmark results are posted as PR comments

Reference

• AirspeedVelocity.jl action: https://github.com/MilesCranmer/AirspeedVelocity.jl
• Example (already using this): https://github.com/QuantumSavory/PBCCompiler.jl/blob/master/.github/workflows/benchmark.yml

🤖 Generated with Claude Code

[Krastanov]

the package server is having an outage, hence all these failures

this changes a workflow that we do not actually use, but it simplifies its potential use in the future and standardizes things across the github org