Cherry-pick "Merge branch 'HDF5BuildUpdate-1.0-20201008' into '1.0'" into master
HDF5 Build Update, 1.0 branch (2020.10.08.)
See merge request !754 (merged)
(cherry picked from commit 3ddbe9db)
- d796bb72 Do not install the PkgConfig files generated for HDF5.
This is meant to fix ATLINFR-3763 for the atlas/athena master builds.