Conda package for M1 MacBook

## 🚀 Feature

## Motivation

Hello, several ML/DL packages are providing direct M1 chip (just CPU) support through conda now e.g., [pytorch/osx-arm64](https://anaconda.org/pytorch/pytorch), I looked around the issues page and discuss.dgl.ai, and I couldn't find a issue tracking this, so I decided to open an issue by myself. Is there a plan to support M1 chip (just CPU) on `dglteam` channel?

## Alternatives
* Compile from source
* Use `x86` conda through rosetta2 emulation, this alternative used to work fine 3-5 months ago but running into issues recently 🙁

## Pitch
* Support `osx-arm64` packages on `dglteam` conda channel
* I'm happy to help in anyway regarding this, I see the build recipes are within `dgl` repo and the build is triggered on Jenkins

## Additional context