Add outputs for dartsim-feedstock

Guidelines for marking packages as broken:

We prefer to patch the repo data (see here) instead of marking packages as broken. This alternative workflow makes environments more reproducible.
Packages with requirements/metadata that are too strict but otherwise work are not technically broken and should not be marked as such.
Packages with missing metadata can be marked as broken on a temporary basis but should be patched in the repo data and be marked unbroken later.
In some cases where the number of users of a package is small or it is used by the maintainers only, we can allow packages to be marked broken more liberally.
We (conda-forge/core) try to make a decision on these requests within 24 hours.

What will happen when a package is marked broken?

Our bots will add the broken label to the package. The main label will remain on the package and this is normal.
Our bots will rebuild our repodata patches to remove this package from the repodata.
In a few hours after the anaconda.org CDN picks up the new patches, you will no longer be able to install the package from the main channel.

[ ] I want to mark a package as broken (or not broken):
- [ ] Added a description of the problem with the package in the PR description.
- [ ] Pinged the team for the package for their input.
[ ] I want to archive a feedstock:
- [ ] Pinged the team for that feedstock for their input.
- [ ] Make sure you have opened an issue on the feedstock explaining why it was archived.
- [ ] Linked that issue in this PR description.
- [ ] Added links to any other relevant issues/PRs in the PR description.
[ ] I want to request (or revoke) access to an opt-in CI resource:
- [ ] Pinged the relevant feedstock team(s)
- [ ] Added a small description explaining why access is needed
[ ] I want to copy an artifact following CFEP-3:
- [ ] Pinged the relevant feedstock team(s)
- [ ] Added a reference to the original PR
- [ ] Posted a link to the conda artifacts
- [ ] Posted a link to the build logs
[x] I want to add a package output to a feedstock:
- [ ] Pinged the relevant feedstock team(s)
- [x] Added a small description of why the output is being added.

Two new outputs have been added to the dartsim feedstock by https://github.com/conda-forge/dartsim-feedstock/pull/75:

dartsim-cpp: This output represents the original C++ library, previously known simply as dartsim.
dartpy: This output provides the Python binding library for dartsim-cpp.

Just so you know, dartsim is now a meta-package that includes dartsim-cpp and dartpy.