Pin pyyaml <6

[mikemhenry]

Checklist

• Used a personal fork of the feedstock to propose changes
• Bumped the build number (if the version is unchanged)
• Reset the build number to 0 (if the version changed)
• Re-rendered with the latest conda-smithy (Use the phrase @conda-forge-admin, please rerender in a comment in this PR for automated rerendering)
• Ensured the license file is being packaged.

[conda-forge-linter]

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) and found it was in an excellent condition.

[mikemhenry]

@conda-forge-admin, please rerender

[mikemhenry]

@jchodera assuming this builds fine, this will fix
#1
choderalab/yank#1264

I will do a more complete fix on the next yak release

[lilyminium]

Just checking in, it would be great to see this update in production! I keep forgetting to pin the yank version myself, and OpenFF Evaluator happily runs for 8 hours before failing here and deleting all intermediate data 😭

[jchodera]

@mikemhenry Can you help get this out if it's ready?

[jchodera]

Approved! Thanks!

[mikemhenry]

@conda-forge-admin, please rerender

[mikemhenry]

@jchodera @jaimergp could one of you merge this in (after CI passes, you should be able to add the auto merge label)? I had forgotten about it, but it is still needed. I've added myself to the maintainers list for future PRs.

[jchodera]

Thanks, @mikemhenry, and apologies for the delay!
Feel free to ping me by slack or email if I'm blocking on this in future.