Add script to build RPM packages for x86_64

[wb8tyw]

Need to use a GitHub action with a Fedora docker container to build RPM packages for lzhuf.

Initial target will be el-8 using either Rocky 8 or AlmaLinux 8 in the chroot used for the build.

[wb8tyw]

Change of plans to just need a mock build script to build RPM packages.

Locally I have an issue that Fedora Docker containers will not work on my Ubuntu 20.04 system.
So I would need to create a VM that can run a Fedora Docker container.

Having this run as a GitHub action is not that useful, as I have no good way to publish the resulting images on a free GitHub organization account.

[wb8tyw]

Closed by mistake.