(WebGL) dynCall are deprecated and not working in Unity6 with Wasm23 enabled

After transfering game to Unity6 i've discovered that it crashes in WebGL builds with cryptic errors:

10:32:41.453 WebGL_Build.framework.js.br:9 Uncaught ReferenceError: dynCall is not defined
    at connection.socket.onopen (WebGL_Build.framework.js.br:9:150900)
connection.socket.onopen @ WebGL_Build.framework.js.br:9

After some investigation i've found that dynCalls are deprecated and not working when wasm 2023 enabled it seems.

For now i've added jspre file with shim to work around this issue but JsWebSocket.jslib need to be updated to use {{{ makeDynCall('vii', 'callback') }}}(1, 2) as per Unity docs.

My shim based on https://github.com/RageAgainstThePixel/com.utilities.websockets/blob/main/Utilities.Websockets/Packages/com.utilities.websockets/Runtime/Plugins/WebSocket.jspre with global dynCall's added is attached for anyone to use while fix is pending - rename to WebSocket.jspre and put into Plugins/WebGL

WebSocket.txt

Start with Unity/JsWebSocket.jslib, then review Unity's deprecated dynCall guidance and the attached WebSocket.jspre shim. Update the WebGL callback invocation to use makeDynCall as described, and verify that a Unity 6 WebGL build with Wasm 2023 no longer reports dynCall as undefined.