Correct gemini's "raid_level" host var to "raid10"

We moved away from raid6 a while back; update the host var to reflect the current configuration.

Correct gemini's "raid_level" host var to "raid10"
7408a94a · Evangelos Foutras · b026a124 · 7408a94a
Verified Commit 7408a94a authored 2 years ago by Evangelos Foutras
--- a/host_vars/gemini.archlinux.org/misc
+++ b/host_vars/gemini.archlinux.org/misc
@@ -12,7 +12,7 @@ system_disks:
  - /dev/sdb
  - /dev/sdc
  - /dev/sdd
-raid_level: "raid6"
+raid_level: "raid10"

 archive_domain: archive.archlinux.org
 wireguard_address: 10.0.0.20