Update pin for dartsim_cpp

[regro-cf-autotick-bot]

This PR has been triggered in an effort to update the pin for dartsim_cpp. The current pinned version is 6.15, the latest available version is 6.16 and the max pin pattern is x.x. This migration will impact 3 feedstocks.

Checklist:

• The new version is a stable supported pin.
• I checked that the ABI changed from 6.15 to 6.16.

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

@conda-forge-admin please ping dartsim

_{This PR was generated by https://github.com/regro/cf-scripts/actions/runs/19269827207 - 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/dartsim 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.