HPX 1.5.0 release candidate 3

The third and last release candidate of HPX 1.5.0 is now available. Get it by cloning the repository and checking out the 1.5.0-rc3 tag or downloading the archive from our releases page: https://github.com/STEllAR-GROUP/hpx/releases/tag/1.5.0-rc3.

The APEX tag has been updated in this release candidate, it includes more algorithms adapted to C++20 and several bug fixes.

While we believe we have sorted out most issues, we ask you to try out the third release candidate and let us know of any issues that you find.