Options become a bunch of session and connection level parameters, and requests do not need to maintain a separate Options object when they contain a body anymore, instead, objects is shared with the session, while request-only parameters get passed downwards to the request and its body. This reduces allocations of Options, currently the heaviest object to manage.
when closed, connections are now placed in a place called eden_connections; whenever a connection is matched for, after checking the live connections and finding none, a match is looked in eden connections; the match is accepted **if** the IP is considered fresh (the input is validated in the cache, or input was an ip or in /etc/hosts, or it's an external socket) and, if a TLS connection, the stored TLS session did not expire; if these conditions do not match, the connection is dropped from the eden and a new connection will started instead; this will therefore allow reusing ruby objects, reusing TLS sessions, and still respect the DNs cache
besides not setting session sni hostname, which it was already doing,
the verify_hostname is set to false to avoid warnings, and the
post_connection_check is still allowed to proceed, to check that the
certificate returned includes the IP address.
port of the similar net-http change found
[here](fa68e64bee)
also ommitting certain steps in the initializer if the ssl socket is
initiated outside of the httpx context and passed as an option.
