tmux:  added additional versions. (#25684)
tmux:  added additional versions. (#25684)

Added sha256 checksums for 3.21, 3.2, 3.1c 3.1a, 3.1, 3.0 and 2.9a.

Co-authored-by: Barry <eb844918cc696b4d877155bf5ae5cc904034c167@llnl.gov>
LLNL/spack,LLNL/spack,LLNL/spack,LLNL/spack,LLNL/spack