Create dir for unpacking of MacOS SDK

[matthiasdiener]

Checklist

• [x] 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 code>@<space/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.

[beckermr]

This PR looks fine. What is the motivation? Did you find an error somewhere in our CI pipelines?

[matthiasdiener]

This PR looks fine. What is the motivation? Did you find an error somewhere in our CI pipelines?

I'm not sure about CI, but an error happens locally when using ./build-locally.py with an $OSX_SDK_DIR that does not exist:

+++ echo 'Downloading 11.0 sdk'
Downloading 11.0 sdk
+++ curl -L -O https://github.com/phracker/MacOSX-SDKs/releases/download/11.3/MacOSX11.0.sdk.tar.xz
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100   627  100   627    0     0   4627      0 --:--:-- --:--:-- --:--:--  4644
100 51.2M  100 51.2M    0     0  57.8M      0 --:--:-- --:--:-- --:--:-- 91.2M
++++ dirname macos/MacOSX11.0.sdk
+++ tar -xf MacOSX11.0.sdk.tar.xz -C macos
tar: could not chdir to 'macos'

[github-actions[bot]]

Hi! This is the friendly conda-forge automerge bot!

I considered the following status checks when analyzing this PR:

• linter: passed
• drone: passed
• travis: passed
• azure: passed

Thus the PR was passing and merged! Have a great day!