Migrating from 0.26 to 0.27

Dropped support for Intel Macs dropped-support-for-intel-macs

We've dropped official support for Intel (x86) maxOS in PR #11719.

This means our Python pheels on PyPi.org and our other pre-built artifact does no longer include Intel Mac binaries.

You can still build Rerun from source. There are instructions for that in BUILD.md.

Support for Python 3.9 is past end-of-life. See https://docs.python.org/3/whatsnew/3.10.html for more details on upgrading to 3.10 if necessary.