`nimble -v` may bootstrap Nim compiler from sources
When Nim executable is not found, then `nimble -v` will try to download and bootstrap the Nim compiler from sources, even though it's not necessary at all to have a working compiler for just showing version info.

It is really an issue because of `choosenim`. `choosenim` tries to call `nimble -v` before it produces a valid symlink to `nim` executable. So, when `nimble -v` is executed, then it tries to boostrap the compiler from sources, leading to much unnecessary CPU usage.

The main outcome of this issue is that running `choosenim update 2.0.6` from scratch takes approximately six minutes, making CI runs last much longer than expected.

Note that Nim 2.0.4 is shipped with a version of `nimble` which doesn't try to bootstrap the compiler on `-v` when it's not found, but fails with an error instead. So, the problem was not visible before Nim 2.0.6 official release.

It's probably also a good idea to fix this issue in `choosenim` by preventing it from calling `nimble -v`.