Create Hetzner cloud servers in Helsinki (Finland)

With Hetzner now having a datacenter in the US[1], we don't want to
accidentally create a server in the US, so let's always create them in
Helsinki where most of our cloud servers are.

[1] https://www.hetzner.com/news/11-21-usa-cloud/

tf-stage1/templates.tf

@@ -110,8 +110,9 @@ resource "hcloud_server" "machine" {
   name        = each.key
   image       = data.hcloud_image.archlinux.id
   server_type = each.value.server_type
+  location    = "hel1"
   lifecycle {
-    ignore_changes = [image]
+    ignore_changes = [image, location]
   }
 }