Remove the apdex from the puma component for the relevant services

Once we've had the new apdex SLI defined in #1228 (closed) running for a while without issue. We could remove the apdex definition from the puma component in (web|api|git).jsonnet.

The apdex value here is likely a double from the new one introduced. If we've done things right, they should look and alert the same on the service overview dashboards. But we're probably better off having them side by side for a while.