add packaging dep

[jhamman]

closes #71

xref: pydata/xarray#6207

Checklist

• Used a personal fork of the feedstock to propose changes
• Bumped the build number (if the version is unchanged)
• 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.

[jhamman]

@conda-forge-admin, please rerender

[github-actions]

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

I tried to rerender for you, but it looks like there was nothing to do.

This message was generated by GitHub actions workflow run https://github.com/conda-forge/xarray-feedstock/actions/runs/1769909751.

[ocefpaf]

@conda-grayskull show requirements

[conda-grayskull]

Working on your request...

[conda-grayskull]

================ HOST ================
Requirements for host

Current Deps	Grayskull found
python >=3.8	python >=3.8	✔️
pip	pip	✔️
setuptools_scm		❌
	setuptools-scm	➕

================ RUN ================
Requirements for run

Current Deps	Grayskull found
python >=3.8	python >=3.8	✔️
numpy >=1.18	numpy >=1.18	✔️
pandas >=1.1	pandas >=1.1	✔️
importlib_metadata		❌
typing_extensions >=3.7		❌
packaging >=20.0		❌

[ocefpaf]

@marcelotrevisani we have setuptools_scm but the bot suggested setuptools-scm. We need to standardized that.
Packaing was found but importlib_metadata and typing_extensions >=3.7 probably have conditionals. I'll check later.

@jhamman sorry to hijack your PR but I wanted to take our new bot for a spin. This one is good to be merged!