5be475f5a2
This allows the Rust HTTP client to be configured to force HTTP/2 even on plaintext connections. This is useful in contexts where the remote server is known to server HTTP/2 over plain text. Added because we use the Synapse Rust HTTP client with the Synapse Pro `event-cache` module. We use this because it's independent from the Python reactor which makes things slower than expected. Currently, the Synapse Rust HTTP client uses HTTP/1 which means a new connection for every request. With HTTP/2, we can share the connection across requests. We want to see if this will make a performance difference and less stress on the database connection situation, see https://github.com/element-hq/synapse-rust-apps/issues/452#issuecomment-3897717599 Here is the sibling PR for using HTTP/2 on the Synapse Pro `event-cache` module side: https://github.com/element-hq/synapse-pro-modules/pull/35