Remove dead permission to access StockLocation

We don't have any UI to edit stock locations. So this ability is unused.

app/models/spree/ability.rb

@@ -35,7 +35,6 @@ module Spree
         can [:read, :update, :destroy], Spree::User, id: user.id
         can [:index, :read], State
         can [:index, :read], StockItem
-        can [:index, :read], StockLocation
         can [:index, :read], StockMovement
         can [:index, :read], Taxon
         can [:index, :read], Variant

spec/models/spree/ability_spec.rb

@@ -125,13 +125,6 @@ RSpec.describe Spree::Ability do
       end
     end
 
-    context 'for StockLocation' do
-      let(:resource) { Spree::StockLocation.new }
-      context 'requested by any user' do
-        it_should_behave_like 'read only'
-      end
-    end
-
     context 'for StockMovement' do
       let(:resource) { Spree::StockMovement.new }
       context 'requested by any user' do