deprecate the client module

Author: atoulme

client/client.go

@@ -75,6 +75,8 @@
 //	      receivers: [otlp]
 //	      processors: [authprinter]
 //	      exporters: [debug]
+//
+// Deprecated [v0.105.0]: use "go.opentelemetry.io/collector/conn" instead.
 package client // import "go.opentelemetry.io/collector/client"
 
 import (