Update dependency hashicorp/nomad to v1.8.4 (#165)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

roles/nomad/defaults/main.yml

@@ -1,7 +1,7 @@
 ---
 
 # renovate: source=github-releases name=hashicorp/nomad
-nomad_version: 1.8.3
+nomad_version: 1.8.4
 
 nomad_bin_dir: /usr/local/share/nomad
 nomad_bin: /usr/bin/nomad