fix audioworklet example local server error

[chaosprint]

The previous server.py will yield an error:

Serving HTTP on :: port 8000 (http://[::]:8000/) ...
::1 - - [10/Mar/2023 11:05:59] "GET / HTTP/1.1" 304 -
::1 - - [10/Mar/2023 11:05:59] "GET /wasm_audio_worklet.js HTTP/1.1" 200 -
::1 - - [10/Mar/2023 11:05:59] "GET /wasm_audio_worklet_bg.wasm HTTP/1.1" 200 -
::1 - - [10/Mar/2023 11:05:59] code 404, message File not found
::1 - - [10/Mar/2023 11:05:59] "GET /favicon.ico HTTP/1.1" 404 -

And it's different from the port 8080 in the README.md.

A minor fix.

[Liamolucko]

What error are you talking about? Do you mean the error your browser will give you trying to navigate to http://[::]:8000? If so, I'm in favour of fixing that, you just haven't made yourself very clear.

Also, the raytrace-parallel example has an identical Python server, so you should do the same for that one too.