Fixes#24873
In KMIP host, do release of a connection (socket) due to our connection pool for the host being full, we currently don't close the connection properly, only rely on destructors.
This just makes sure `release` closes the connection if it neither retains or caches it.
Also, when running with the PyKMIP fixture, we tested the port being reachable using a normal socket. This makes python SSL generate errors -> log noise that look like actual errors.
Change the test setup to use a proper TLS connection + proper shutdown to avoid the noise logs.
This also adds a fixture helper for processes, and moves EAR test to use it (and by extension, seastar::experimental::process) instead of boost::process, removing a nasty non-seastarish dependency.
Closesscylladb/scylladb#24874
* github.com:scylladb/scylladb:
encryption_test: Make PyKMIP run under seastar::experimental::process
test/lib: Add wrapper helper for test process fixtures
kmip_host: Close connections properly if dropped by pool being full
encryption_at_rest_test: Do port check using TLS