chore: Release 0.7.0

[sbernauer]

Changed

• Switch from the older (forked) prusto crate to trino-rust-client (#116).

Fixed

• Handle Redis connection errors (e.g. broken pipe during master failover) gracefully instead of panicking.
  Previously, get_queued_query_count would .unwrap() on the Redis result, causing a panic that poisoned
  the metrics RwLock, cascading into further panics and leaving pods unresponsive (#111).
• Point the forwarding related headers (Host, X-Forwarded-Host, X-Forwarded-Proto and
  X-Forwarded-Port) of proxied client requests at the configured externalEndpoint of the Trino
  cluster. Trino builds the absolute URLs it hands out to clients from these headers, so previously
  they pointed at trino-lb. Most notably this broke the OAuth 2.0 flow: Trino put the trino-lb
  address into the x_redirect_server and x_token_server of its WWW-Authenticate challenge, so
  clients were sent to https://<trino-lb>/oauth2/token/{id}, which trino-lb answered with a 404.
  The RFC 7239 Forwarded header is now removed as well, as it takes precedence over the
  X-Forwarded-* headers. This is a no-op for Trino clusters without an externalEndpoint (#119).