[nim] update to 2.2.6

[RickBarretto]

Package name

mingw-w64-nim

New version number

2.2.6

Other information that may be useful

The current version is 1.6.20, which is very outdated considering we have a new major version.

Are you willing to submit a PR?

No response

[striezel]

Update of nim to the new major version 2.x has been tried before in #22413, but there were build errors for the Clang environment. However, that attempt was a while ago, so maybe somebody should give it another try.

[RickBarretto]

@striezel I was able to compile nim on Msys2's Mingw64 manually and worked quite fine.
I don't know about creating a package for this, which additional steps are required...

[striezel]

Mingw64 wasn't the problematic part, Clang64 was.

What version of nim did you build? 2.2.6?

[RickBarretto]

What version of nim did you build? 2.2.6?

Yes! But actually on Mingw64. Never tried Clang64.