Remove `dashboard_context` (conversation at https://github.com/thoughtbot/administrate/pull/2457)

remove-dashboard_context.diff

diff --git a/lib/administrate/field/has_many.rb b/lib/administrate/field/has_many.rb
index 5197767c..70f91b30 100644
--- a/lib/administrate/field/has_many.rb
+++ b/lib/administrate/field/has_many.rb
@@ -28,7 +28,6 @@ module Administrate
           collection_attributes: options[:collection_attributes]
         ).tap do |page|
           page.context = context
-          page.dashboard_context = context
         end
       end

diff --git a/lib/administrate/field/has_one.rb b/lib/administrate/field/has_one.rb
index 1ef83f5a..491bc03f 100644
--- a/lib/administrate/field/has_one.rb
+++ b/lib/administrate/field/has_one.rb
@@ -28,7 +28,6 @@ module Administrate
           data || resolver.resource_class.new
         ).tap do |page|
           page.context = context
-          page.dashboard_context = context
         end
       end

@@ -38,7 +37,6 @@ module Administrate
           data || resolver.resource_class.new
         ) do |page|
           page.context = context
-          page.dashboard_context = context
         end
       end

diff --git a/lib/administrate/page/base.rb b/lib/administrate/page/base.rb
index be7fbc1f..cbe8d21f 100644
--- a/lib/administrate/page/base.rb
+++ b/lib/administrate/page/base.rb
@@ -29,10 +29,6 @@ module Administrate

       attr_accessor :context

-      def dashboard_context=(context)
-        dashboard.context = context
-      end
-
       private

       def attribute_field(dashboard, resource, attribute_name, page)