Remove seemingly unused context stubs code

src/spectator/mocks/registry.cr

@@ -11,23 +11,6 @@ module Spectator::Mocks
     @all_instances = {} of String => Entry
     @entries = {} of Key => Entry
 
-    def initialize(context : TestContext)
-      current_context = context
-      while current_context
-        current_context.stubs.each do |k, v|
-          stubs = if @all_instances.has_key?(k)
-                    @all_instances[k].stubs
-                  else
-                    entry = Entry.new
-                    @all_instances[k] = entry
-                    entry.stubs
-                  end
-          stubs.concat(v)
-        end
-        current_context = current_context.parent?
-      end
-    end
-
     def reset : Nil
       @entries.clear
     end