Assert on the count instead of specific model

Fixes a flaky spec because the returned record here is non
deterministic

spec/finders/protected_branches_finder_spec.rb

@@ -30,7 +30,7 @@ describe ProtectedBranchesFinder do
       end
 
       it 'returns limited protected branches of project' do
-        expect(subject).to eq([another_protected_branch])
+        expect(subject.count).to eq(1)
       end
     end
   end

spec/models/project_spec.rb

@@ -5718,7 +5718,7 @@ describe Project do
     subject { project.limited_protected_branches(1) }
 
     it 'returns limited number of protected branches based on specified limit' do
-      expect(subject).to eq([another_protected_branch])
+      expect(subject.count).to eq(1)
     end
   end