[ofiwg] libfabric 2.4.0rc2 is out

[Xiong, Jianxin]

The release tarballs are available at: https://github.com/ofiwg/libfabric/releases/tag/v2.4.0rc2 

The integrity of the packages can be verified by downloading the `.asc` files and running the following commands:

    gpg --import public_key.asc
    gpg --verify libfabric-2.4.0rc2.tar.bz2.asc libfabric-2.4.0rc2.tar.bz2
    gpg --verify fabtests-2.4.0rc2.tar.bz2.asc fabtests-2.4.0rc2.tar.bz2
 
Starting now, only critical bug fixes can be merged to the v2.4.x branch before GA, which is planned for 12/15.
 
Jianxin Xiong
Fabric Software
Intel Corporation
Jianxin.xiong at intel.com