Remove unneeded "formulae exist" test

Library/Homebrew/test/support/helper/spec/shared_examples/formulae_exist.rb

@@ -1,13 +0,0 @@
-# typed: false
-# frozen_string_literal: true
-
-shared_examples "formulae exist" do |array|
-  array.each do |f|
-    it "#{f} formula exists" do
-      core_tap = Pathname("#{HOMEBREW_LIBRARY_PATH}/../Taps/homebrew/homebrew-core")
-      formula_path = core_tap/"Formula/#{f}.rb"
-      alias_path = core_tap/"Aliases/#{f}"
-      expect(formula_path.exist? || alias_path.exist?).to be true
-    end
-  end
-end