Formatting and cope with more modern RSpec config changes

Co-authored-by: Ruoyu Zhong <zhongruoyu@outlook.com>

Author: issyl0

Library/Homebrew/rubocops/resource_requires_dependencies.rb

@@ -24,7 +24,7 @@ def audit_formula(_node, _class_node, _parent_class_node, body_node)
           return if dependencies.include?("libxml2") && dependencies.include?("libxslt")
 
           offending_node(lxml)
-          problem "Add `uses_from_macos` lines above for \"libxml2\"` and \"libxslt\"."
+          problem "Add `uses_from_macos` lines above for `\"libxml2\"` and `\"libxslt\"`."
         end
       end
     end

Library/Homebrew/test/rubocops/resource_requires_dependencies_spec.rb

@@ -2,7 +2,7 @@
 
 require "rubocops/resource_requires_dependencies"
 
-describe RuboCop::Cop::FormulaAudit::ResourceRequiresDependencies do
+RSpec.describe RuboCop::Cop::FormulaAudit::ResourceRequiresDependencies do
   subject(:cop) { described_class.new }
 
   context "when a formula does not have the lxml resource" do
@@ -51,7 +51,7 @@ class Foo < Formula
           uses_from_macos "not_libxml2"
 
           resource "lxml" do
-          ^^^^^^^^^^^^^^^ FormulaAudit/ResourceRequiresDependencies: Add `uses_from_macos` lines above for "libxml2"` and "libxslt".
+          ^^^^^^^^^^^^^^^ FormulaAudit/ResourceRequiresDependencies: Add `uses_from_macos` lines above for `"libxml2"` and `"libxslt"`.
             url "blah"
             sha256 "blah"
           end