alternate libint2 for psi4

[loriab]

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.

This is based on the discussion in #15 and uses the recipe from staged-recipes. I'm trying this as a dev package so that it doesn't disrupt current users and doesn't put non-upstream-merged code on main c-f channel. Experimenting for now.

closes conda-forge/staged-recipes#22060
closes #15
closes #16
closes loriab/psi4-binder#3
closes loriab/psi4-binder#36
closes loriab/psi4-binder#38

[conda-forge-webservices]

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

I wanted to let you know that I linted all conda-recipes in your PR (recipe) and found some lint.

Here's what I've got...

For recipe:

• pin_compatible should be used instead of pin_subpackage for libint2 because it is not a known output of this recipe: ['libint'].

[conda-forge-webservices]

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.

[loriab]

@conda-forge-admin, please rerender

[loriab]

I guess this is plausibly ready for review @felipeZ . Glad to answer any questions.