cd: drop the two informers the notification subsystem left behind

v3.6.0-.2 could not start. hanzocd-server crash-looped:

  fatal: Recovered from panic: nil pointer dereference
  server.(*ArgoCDServer).Init -> server/server.go:554

configMapInformer and secretInformer were declared on the struct and Run() in
Init(), but never assigned anywhere in the repo. b2d7140a (delete the
notification subsystem) removed their construction —

  secretInformer := k8s.NewSecretInformer(..., "cd-notifications-secret")
  configMapInformer := k8s.NewConfigMapInformer(..., "cd-notifications-cm")

— which fed api.NewFactory for notifications and nothing else. The fields and
the two Run() calls survived the deletion, so both were nil at boot.

Deleted rather than reconstructed: they watched notification config, and there
is no notification subsystem to configure. We use hanzoai/notify.

Worth naming the class, because it is the third time tonight: a nil interface
field is valid Go, so `go build ./...` passed clean and said nothing. Same
shape as the Register* seams and the mounted globals — it compiles, and it
yields the zero value.

The "secret key does not exist in secret" warning on the preceding line is
unrelated; hanzocd-secret carries all five keys and works on sha-e1b9244.

Co-authored-by: Hanzo Dev <[email protected]>

server/server.go

@@ -204,8 +204,6 @@ type ArgoCDServer struct {
 	indexData          []byte
 	indexDataErr       error
 	staticAssets       http.FileSystem
-	secretInformer     cache.SharedIndexInformer
-	configMapInformer  cache.SharedIndexInformer
 	serviceSet         *ArgoCDServiceSet
 	extensionManager   *extension.Manager
 	Shutdown           func()
@@ -551,8 +549,6 @@ func (server *ArgoCDServer) Init(ctx context.Context) {
 	go server.appInformer.Run(ctx.Done())
 	go server.appsetInformer.Run(ctx.Done())
 	go server.clusterInformer.Run(ctx.Done())
-	go server.configMapInformer.Run(ctx.Done())
-	go server.secretInformer.Run(ctx.Done())
 }
 
 // Run runs the API Server