chore(infra): Remove project owners that are no longer owners (#7297)

Now Terraform is receiving a 400 from the Google API because these users
don't exist... 🙃.

Hopefully the cycle was broken by the last PR and this one succeeds.

terraform/environments/production/main.tf

@@ -1,8 +1,6 @@
 locals {
   project_owners = [
-    "a@firezone.dev",
     "bmanifold@firezone.dev",
-    "gabriel@firezone.dev",
     "jamil@firezone.dev",
   ]