There was something like that on Reddit but I can’t remember the sub. I haven’t seen one here. The best way to get reviews of open source is via contributions to larger projects. That of course doesn’t answer your question directly but is worth noting.

I’d recommend joining some discord or matrix servers for the language you work in or likeminded folk. They tend to have channels for that, and some have really helpful communities.

eta: I just checked my local instance and saw a community with very few subs and zero posts called /c/reviewmycode. Somebody has to post first.