Add utilization metrics

[samuel-williams-shopify]

Summary

• add async-utilization as a dependency for limiter telemetry counters
• accept registry-like utilization objects in limiter constructors
• write acquired, available, waiting, and reacquire-waiting metrics at limiter state transitions

Tests

• PATH="$HOME/.rubies/ruby-3.4.4/bin:$PATH" bundle exec sus
• PATH="$HOME/.rubies/ruby-3.4.4/bin:$PATH" bundle exec rubocop
• PATH="$HOME/.rubies/ruby-3.4.4/bin:$PATH" bundle exec bake decode:index:coverage lib