[ofiwg] libfabric v1.21.0 and v1.20.2 are now available

[Xiong, Jianxin]

The libfabric community is happy to announce that the newest release, v1.21.0, 
of libfabric and fabtests is now available:

https://github.com/ofiwg/libfabric/releases/tag/v1.21.0

A new provider, cxi, has been added in this release.

The bug fix release for the 1.20 series, v1.20.2, is now available at:

https://github.com/ofiwg/libfabric/releases/tag/v1.20.2

The list of changes is available in:

https://github.com/ofiwg/libfabric/blob/v1.21.x/NEWS.md
https://github.com/ofiwg/libfabric/blob/v1.20.x/NEWS.md

-Jianxin