Manually migrate to python 3.10

[xylar]

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)
• [x] 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)
• [x] 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.

[xylar]

@conda-forge-admin, please rerender

[xylar]

First problem: https://github.com/conda-forge/airflow-feedstock/blob/4ac155da8580760434b24a00c27000034036be35/recipe/meta.yaml#L92 sqlachemy<1.4.26 was never build with python 3.10.

I'm closing this and assuming the next airflow release will support python 3.10