v3.5.0

• Update matrix-rust-sdk version, providing several changes including a fix
  for occasional freezes (element-hq/element-web#26488).

• New API OlmMachine.requestMissingSecretsIfNeeded that creates an
  outgoing secret request to other sessions.

• Verification cancel codes for cancelWithCode and cancelInfo.cancelCode
  are now passed as strings rather than an enum.