Move the buildkite bin to the end of $PATH
Move the buildkite bin to the end of $PATH

The buildkite bin might be /usr/bin on some systems, and then you end up with
an unusual path. There's no need for ours to be at the front.

Shopify/agent,Shopify/agent,buildkite/agent,Shopify/agent,buildkite/agent,buildkite/agent