CHANGELOG: manylinux_2_28 is more like 2019 (#14696)
I must have Googled something too fast, sorry. glibc 2.28 came out
August 2018, Fedora 29 was the earliest to ship with it in October 2018,
Debian 10 shipped with it in July 2019, and CentOS 8 shipped with it in
September 2019.
