[FR] Mac Catalyst support for Firebase C++ SDK

[b0f1df79]

I found out you guys don't provide a library for Mac Catalyst.
But in apple.toolchain.cmake I see you still support building libraries for Mac Catalyst.
So, are you planning to provide the library for Mac Catalyst? Or do users have to build their own libraries when needed?
Thanks

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[chkuang-g]

Hi @ryuw0n

Firebase iOS SDK rolled out macOS Catalyst beta support from 8.9.0
https://firebase.google.com/support/release-notes/ios#version_890_-_october_28_2021

However, C++ SDK does not support this yet.

Let me turn this into FR. If anyone is interested in this, please upvote.

Shawn