[rubygems/rubygems] use Rubocop Lint/Debugger check rather than custom spec

We have a quality spec that check for debugger statements. Rubocop has a
cop that tests for the same thing. As such it makes sense to remove the
spec and activate the cop.

https://github.com/rubygems/rubygems/commit/dc1eb6eec5

spec/bundler/quality_spec.rb

@@ -3,25 +3,6 @@
 require "set"
 
 RSpec.describe "The library itself" do
-  def check_for_debugging_mechanisms(filename)
-    debugging_mechanisms_regex = /
-      (binding\.pry)|
-      (debugger)|
-      (sleep\s*\(?\d+)|
-      (fit\s*\(?("|\w))
-    /x
-
-    failing_lines = []
-    each_line(filename) do |line, number|
-      if line =~ debugging_mechanisms_regex && !line.end_with?("# ignore quality_spec\n")
-        failing_lines << number + 1
-      end
-    end
-
-    return if failing_lines.empty?
-    "#{filename} has debugging mechanisms (like binding.pry, sleep, debugger, rspec focusing, etc.) on lines #{failing_lines.join(", ")}"
-  end
-
   def check_for_git_merge_conflicts(filename)
     merge_conflicts_regex = /
       <<<<<<<|
@@ -125,16 +106,6 @@ RSpec.describe "The library itself" do
     expect(error_messages.compact).to be_well_formed
   end
 
-  it "does not include any leftover debugging or development mechanisms" do
-    exempt = %r{quality_spec.rb|support/helpers|vcr_cassettes|\.md|\.ronn|index\.txt|\.5|\.1}
-    error_messages = []
-    tracked_files.each do |filename|
-      next if filename =~ exempt
-      error_messages << check_for_debugging_mechanisms(filename)
-    end
-    expect(error_messages.compact).to be_well_formed
-  end
-
   it "does not include any unresolved merge conflicts" do
     error_messages = []
     exempt = %r{lock/lockfile_spec|quality_spec|vcr_cassettes|\.ronn|lockfile_parser\.rb}