Remove unused vote extensions methods

These methods aren't used since commit b98244afd.

config/initializers/vote_extensions.rb

@@ -13,18 +13,6 @@ ActsAsVotable::Vote.class_eval do
           Comment.public_for_api.pluck(:id))
   end
 
-  def self.for_debates(debates)
-    where(votable_type: "Debate", votable_id: debates)
-  end
-
-  def self.for_proposals(proposals)
-    where(votable_type: "Proposal", votable_id: proposals)
-  end
-
-  def self.for_legislation_proposals(proposals)
-    where(votable_type: "Legislation::Proposal", votable_id: proposals)
-  end
-
   def self.for_budget_investments(budget_investments = Budget::Investment.all)
     where(votable_type: "Budget::Investment", votable_id: budget_investments)
   end

spec/models/vote_spec.rb

@@ -1,32 +1,6 @@
 require "rails_helper"
 
 describe Vote do
-  describe "#for_debates" do
-    it "does not returns votes for other votables" do
-      debate = create(:debate)
-      create(:vote, votable: create(:comment))
-
-      expect(Vote.for_debates(debate).count).to eq(0)
-    end
-
-    it "returns votes only for debates in parameters" do
-      debate1 = create(:debate, voters: [create(:user)])
-      debate2 = create(:debate)
-
-      expect(Vote.for_debates(debate1).count).to eq(1)
-      expect(Vote.for_debates(debate2).count).to eq(0)
-    end
-
-    it "accepts more than 1 debate" do
-      debate1 = create(:debate, voters: [create(:user)])
-      debate2 = create(:debate)
-      debate3 = create(:debate, voters: [create(:user)])
-
-      expect(Vote.for_debates([debate1, debate2]).count).to eq(1)
-      expect(Vote.for_debates([debate1, debate3]).count).to eq(2)
-    end
-  end
-
   describe "#value" do
     it "returns vote flag" do
       vote = create(:vote, vote_flag: true)