Revert "formulary: install tap if needed."

Library/Homebrew/formulary.rb

@@ -279,8 +279,6 @@ module Formulary
     end
 
     def load_file
-      tap.install unless tap.installed?
-
       super
     rescue MethodDeprecatedError => e
       e.issues_url = tap.issues_url || tap.to_s

Library/Homebrew/test/formulary_spec.rb

@@ -227,8 +227,7 @@ describe Formulary do
       end
     end
 
-    it "raises an error if the Formula is not available after tapping" do
-      expect_any_instance_of(Tap).to receive(:install)
+    it "raises an error if the Formula is not available" do
       expect {
         described_class.to_rack("a/b/#{formula_name}")
       }.to raise_error(TapFormulaUnavailableError)