Update to `prometheus_client` v0.24

[SimenB]

https://github.com/prometheus/client_rust/releases/tag/v0.24.0

[SimenB]

@olix0r ping, in case you missed it 😀 (I may be able to provide a PR if you're open for it)

[olix0r]

Thanks, we'll pick this up with the next kube bump. I expect that should be soon, but it takes a bit of coordination on our end.