Complement `TestRestrictedRoomsRemoteJoinLocalUserInMSC3787Room` flake

[squahtx]

https://github.com/matrix-org/synapse/actions/runs/5219185927/jobs/9420734656

  2023/06/09 07:33:42 Sharing [SERVER_NAME=hs1 SYNAPSE_WORKER_TYPES= SYNAPSE_LOG_TESTING=1 SYNAPSE_COMPLEMENT_USE_WORKERS=true SYNAPSE_COMPLEMENT_DATABASE=postgres] host environment variables with container
  2023/06/09 07:33:42 Sharing [SERVER_NAME=hs2 SYNAPSE_WORKER_TYPES= SYNAPSE_LOG_TESTING=1 SYNAPSE_COMPLEMENT_USE_WORKERS=true SYNAPSE_COMPLEMENT_DATABASE=postgres] host environment variables with container
      restricted_rooms_test.go:230: Deploy times: 27.295222ms blueprints, 18.102995982s containers
      client.go:740: [CSAPI] POST hs2/_matrix/client/v3/createRoom => 200 OK (982.812319ms)
      client.go:740: [CSAPI] POST hs2/_matrix/client/v3/createRoom => 200 OK (901.180753ms)
      client.go:740: [CSAPI] POST hs2/_matrix/client/v3/rooms/!RNbMtrFvXVNGXdnxkL:hs2/invite => 200 OK (1.937303493s)
      client.go:740: [CSAPI] POST hs1/_matrix/client/v3/join/!RNbMtrFvXVNGXdnxkL:hs2 => 200 OK (1.902639747s)
      client.go:740: [CSAPI] POST hs1/_matrix/client/v3/rooms/!RNbMtrFvXVNGXdnxkL:hs2/invite => 403 Forbidden (156.64856ms)
      client.go:740: [CSAPI] POST hs1/_matrix/client/v3/join/!RNbMtrFvXVNGXdnxkL:hs2 => 502 Bad Gateway (79.363191ms)
      client.go:740: [CSAPI] POST hs1/_matrix/client/v3/join/!PGWzBHOhHxrJlRQlPa:hs2 => 200 OK (695.280724ms)
      client.go:740: [CSAPI] POST hs1/_matrix/client/v3/join/!RNbMtrFvXVNGXdnxkL:hs2 => 502 Bad Gateway (44.26954ms)
      restricted_rooms_test.go:292: CSAPI.MustDoFunc POST http://127.0.0.1:33430/_matrix/client/v3/join/%21RNbMtrFvXVNGXdnxkL:hs2?server_name=hs1 returned non-2xx code: 502 Bad Gateway - body: {"errcode":"M_UNKNOWN","error":"Failed to make_join via any server"}