Change base image of build images from AlmaLinux8

[vicentebolea]

Why is this feature important? E4S spack buildcache does not build AlmaLinux8 binaries thus we can not take advantage of that

What is the potential impact of this feature in the community? Dramatically increase the build time of our CI images.

Describe the solution you'd like and potential required effort We have to first determined the "most" compatible distro, adapt the image building script, and trigger the builds.

Note: contents adapted from the VTK contribution guidelines

[vicentebolea]

cc @chuckatkins

[vicentebolea]

A solution seems to use rocky8 and force Spack to set its os to rhel8

[vicentebolea]

both rocky and alma would allow, however, it seems that rocky is gaining more traction as the successor of centos

[vicentebolea]

Closing this as the this issue is unclear the title speaks of Ubuntu and the comments about Alma and then Rocky. Lets move this to a per-build case.