Update pin for ruby

[regro-cf-autotick-bot]

This PR has been triggered in an effort to update the pin for ruby. The current pinned version is 2.6, the latest available version is 3.4 and the max pin pattern is x.x. This migration will impact 17 feedstocks.

Checklist:

• The new version is a stable supported pin.
• I checked that the ABI changed from 2.6 to 3.4.

**Please note that if you close this PR we presume that the new pin has been rejected.

@conda-forge-admin please ping ruby

_{This PR was generated by https://github.com/regro/cf-scripts/actions/runs/12492388643 - please use this URL for debugging.}

[conda-forge-webservices]

Hi! This is the friendly automated conda-forge-webservice.

I was asked to ping @conda-forge/ruby and so here I am doing that.

[conda-forge-admin]

Hi! This is the friendly automated conda-forge-linting service.

I just wanted to let you know that I linted all conda-recipes in your PR (recipe/meta.yaml) and found it was in an excellent condition.

[h-vetinari]

C.f. #4805; the feedstock seems to have gotten a bit more activity again this year, but AFAIU that's just for ruby itself, not for the ecosystem. In that case, we should not migrate.