Announcing Apptainer 1.4.0

['Dave Dykstra' via announce]

Apptainer 1.4.0 is now available. There were a few changes since
1.4.0-rc.2 but they were minor so we decided to not put out a third
release candidate. The combined set of release notes of all changes
since 1.3.6 is at
https://github.com/apptainer/apptainer/releases/tag/v1.4.0
and at the bottom is the list of changes since 1.4.0-rc.2.

There have been many changes since 1.3.6 so please test it soon and
report any problems to https://github.com/apptainer/apptainer/issues.

Dave