Remove obsolete expectations in budget index test

We forgot to do so in commit 04605d5d5. Before that commit, we were
testing the links weren't displayed in the "informing" phase as opposed
to the "finished" phase. After that commit, they weren't displayed
anywhere since a <select> field was shown instead.

Since then, we've replaced the <select> field with the links generated
by the `Budgets::Investments::FiltersComponent`. We've already got tests
for these links.

spec/system/budgets/budgets_spec.rb

@@ -96,10 +96,6 @@ describe "Budgets" do
       within("#budget_info") do
         expect(page).not_to have_link heading.name
         expect(page).to have_content "#{heading.name}\n€1,000,000"
-
-        expect(page).not_to have_link("List of all investment projects")
-        expect(page).not_to have_link("List of all unfeasible investment projects")
-        expect(page).not_to have_link("List of all investment projects not selected for balloting")
       end
     end