feat(ops/glesys): add DNS record for A sanduny.tvl.su.

Change-Id: I12e678f161ca9bfb7e982ed067a0b8bd0325d737
Reviewed-on: https://cl.tvl.fyi/c/depot/+/5296
Reviewed-by: sterni <sternenseemann@systemli.org>
Autosubmit: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI

ops/glesys/main.tf

@@ -60,3 +60,8 @@ variable "whitby_ipv6" {
   type    = string
   default = "2a01:4f8:242:5b21:0:feed:edef:beef"
 }
+
+variable "sanduny_ipv4" {
+  type    = string
+  default = "85.119.82.231"
+}