The testing is done via a new library used to spin up an ephemeral
Kubernetes cluster using `kind`. It interacts with `kind` by shelling
out; I'm not happy about this, but I can't find an equivalent library
for Rust.

Unfortunately, kube doesn't work with rustls when talking to local
clusters: kube-rs/kube#153

Thankfully, openssl is only a dependency if the test-utils feature is
enabled, so our release builds will not depend on openssl.
Unfortunately, that means that our release builds will be interacting
with Kubernetes using a different TLS library than our tests use.

It's no longer necessary since the crate features are set up to
(rightfully) not include openssl in release builds.

Also, update a stale reference to "PPM" as the protocol name to "DAP".