Fix issuable state caching

We were including controller params in the cache key, so the key for the header
didn't match the one for the list itself!

app/controllers/concerns/issuable_collections.rb

@@ -32,10 +32,10 @@ module IssuableCollections
 
   def filter_params
     set_sort_order_from_cookie
-    set_default_scope
     set_default_state
 
-    @filter_params = params.dup
+    # Skip irrelevant Rails routing params
+    @filter_params = params.dup.except(:controller, :action, :namespace_id)
     @filter_params[:sort] ||= default_sort_order
 
     @sort = @filter_params[:sort]
@@ -55,10 +55,6 @@ module IssuableCollections
     @filter_params
   end
 
-  def set_default_scope
-    params[:scope] = 'all' if params[:scope].blank?
-  end
-
   def set_default_state
     params[:state] = 'opened' if params[:state].blank?
   end

app/finders/issuable_finder.rb

@@ -22,7 +22,7 @@ class IssuableFinder
   include CreatedAtFilter
 
   NONE = '0'.freeze
-  IRRELEVANT_PARAMS_FOR_CACHE_KEY = %i[utf8 sort page].freeze
+  IRRELEVANT_PARAMS_FOR_CACHE_KEY = %i[utf8 sort page state].freeze
 
   attr_accessor :current_user, :params