message: build: Add tokio, revert serialport update
  Add tokio for broadcaster, move serialport back to v3 until we
  have time to figure out the new constructors.
diff: @@ -75,9 +75,10 @@ tracing-futures = "0.2.4"
  tracing-subscriber = { version = "0.2.15", features = ["json"] }
  dashmap = "4.0.0-rc6"
  displaydoc = "0.1.7"
  -serialport = { version = "4.0.0", optional = true }
  +serialport = { version = "3.3.0", optional = true }
  hidapi = { version = "1.2.5", optional = true }
  wasm-bindgen = { version = "0.2.69", optional = true }
  +tokio = { version = "0.3.6", features = ["sync"] }
  [target.'cfg(windows)'.dependencies]
  rusty-xinput = "1.2.0"
  