[clsi-lb] speed up refreshing server list from GCP (#34478)

* [clsi-lb] move retries to the individual GCP API call

* [clsi-lb] fix docker-compose.gcp.yml

* [clsi-lb] collect per-zone/per-group instances in parallel

* [clsi-lb] re-use the compute GCP client

GitOrigin-RevId: 46f7f89b0ddea061ed4df4df2fdbcb315f19cbaa

yarn.lock

@@ -6474,6 +6474,7 @@ __metadata:
   resolution: "@overleaf/clsi-lb@workspace:services/clsi-lb"
   dependencies:
     "@overleaf/logger": "workspace:*"
+    "@overleaf/o-error": "workspace:*"
     "@overleaf/settings": "workspace:*"
     "@overleaf/stream-utils": "workspace:*"
     chai-as-promised: "npm:^7.1.1"