Add visionOS support

[bmueller]

New Feature / Enhancement Checklist

• [x ] I am not disclosing a vulnerability.
• [s ] I am not just asking a question.
• [s ] I have searched through existing issues.

Current Limitation

I am unable to build a project for visionOS using the SPM version of the Parse SDK.

Feature / Enhancement Description

Because the package doesn't reference the "vision" target in code, when you build for visionOS it just tries to include AppKit code.

Example Use Case

Alternatives / Workarounds

3rd Party References

[parse-github-assistant]

Thanks for opening this issue!

• 🎉 We are excited about your ideas for improvement!

[bmueller]

I made the necessary changes to get the project building for visionOS here: https://github.com/bmueller/Parse-SDK-iOS-OSX

[mtrezza]

Thanks for sharing @bmueller, would you want to open a PR? We'd be happy to review.

[bmueller]

Done! #1762

[bmueller]

Why was this never merged?

[mtrezza]

@bmueller there has been feedback on your PR and it seems that was never followed up on, see #1762 (comment).