Nim 2.0.4 and 1.6.20 released

[miran]

We have released two patch releases for Nim:

  * Nim 2.0.4
  * Nim 1.6.20 (LTS)



For more information, [see the website 
article](https://nim-lang.org/blog/2024/04/16/versions-1620-204-released.html).