Chronos coro prime sieve

[Clemente90]

• 3.nim no changes.
• 4.nim same file as 3.nim but uses the chronos backend instead of std/asyncdispatch.
• bench_nim.yaml added 4.nim to the list and added compiler optimization flags for gcc.
• app.nimble added chronos dependency. (I saw rust solutions with tokio so I assume chronos is fine).

[Clemente90]

@hanabi1224, I don't know why wasm failed.

[Clemente90]

@hanabi1224 locally run with this repo's harness:

Descriptions

1.nim = using Nim's experimental coro module
3.nim = using asyncdispatch module with my trivial channel
4.nim = using chronos library with my trivial channel
5.nim = using chronos library with chronos's channel
6.nim = using chronos and yasync libraries with yasync's trivial channel

input size 1000

1.nim = 2092.2571
3.nim = 347.0564
4.nim = 157.4326
5.nim = 154.1886
6.nim = 18.504

input size 4000

1.nim = TIMEOUT
3.nim = TIMEOUT
4.nim = 2361.104
5.nim = 2317.1114
6.nim = 267.6666

[Clemente90]

Run ./.github/python.sh
Python 3.13.5
--2025-07-29 01:22:35--  https://github.com/pyston/pyston/releases/download/pyston_2.3.5/pyston_2.3.5_portable_amd64.tar.gz
Resolving github.com (github.com)... 140.82.116.3
Connecting to github.com (github.com)|140.82.116.3|:443... connected.
HTTP request sent, awaiting response... 503 Service Unavailable
2025-07-29 01:22:38 ERROR 503: Service Unavailable.

tar: This does not look like a tar archive

gzip: stdin: unexpected end of file
tar: Child returned status 1
tar: Error is not recoverable: exiting now
./.github/python.sh: 17: cd: can't cd to pyston_2.3.5
./.github/python.sh: 19: pyston3: not found
Error: Process completed with exit code 127.

@hanabi1224 The workflow errored on an HTTP request for Pyston. Its unrelated to my changes.
However, when I ran the full bench I did see that my change affected the Nim mandelbrot test. I'll look into that.

[Clemente90]

@hanabi1224 I think it should be all set. I de-listed 4.nim too.