Add 2-8 zfs-release RPMs for EL8-9, sign EL10 RPMs (#105)

- Rebuild 2-8 zfs-release RPMs for EL8-9
- Sign the EL10 RPMs (this was missed in previous commit)

Signed-off-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>

Author: tonyhutter