Remove old os/mac/formula spec

Library/Homebrew/test/os/mac/formula_spec.rb

-# frozen_string_literal: true
-
-require "formula"
-
-describe Formula do
-  describe "#uses_from_macos" do
-    before do
-      sierra_os_version = OS::Mac::Version.from_symbol(:sierra)
-
-      allow(OS).to receive(:mac?).and_return(true)
-      allow(OS::Mac).to receive(:version).and_return(OS::Mac::Version.new(sierra_os_version))
-    end
-
-    it "doesn't adds a dependency if it doesn't meet OS version requirements" do
-      f = formula "foo" do
-        url "foo-1.0"
-
-        uses_from_macos("foo", after: :high_sierra)
-        uses_from_macos("bar", before: :el_capitan)
-      end
-
-      expect(f.class.stable.deps).to be_empty
-      expect(f.class.devel.deps).to be_empty
-      expect(f.class.head.deps).to be_empty
-    end
-
-    it "allows specifying dependencies after certain version" do
-      f = formula "foo" do
-        url "foo-1.0"
-
-        uses_from_macos("foo", after: :el_capitan)
-      end
-
-      expect(f.class.stable.deps.first.name).to eq("foo")
-      expect(f.class.devel.deps.first.name).to eq("foo")
-      expect(f.class.head.deps.first.name).to eq("foo")
-    end
-
-    it "allows specifying dependencies before certain version" do
-      f = formula "foo" do
-        url "foo-1.0"
-
-        uses_from_macos("foo", before: :high_sierra)
-      end
-
-      expect(f.class.stable.deps.first.name).to eq("foo")
-      expect(f.class.devel.deps.first.name).to eq("foo")
-      expect(f.class.head.deps.first.name).to eq("foo")
-    end
-
-    it "raises an error if passing invalid OS versions" do
-      expect {
-        formula "foo" do
-          url "foo-1.0"
-
-          uses_from_macos("foo", after: "bar", before: :mojave)
-        end
-      }.to raise_error(ArgumentError, 'unknown version "bar"')
-    end
-  end
-end