[rubygems/rubygems] Remove compatibility code with old RubyGems

https://github.com/rubygems/rubygems/commit/f11e42a3c5

lib/bundler.rb

@@ -577,7 +577,7 @@ module Bundler
 
       requested_path_gems = definition.requested_specs.select {|s| s.source.is_a?(Source::Path) }
       path_plugin_files = requested_path_gems.map do |spec|
-        Bundler.rubygems.spec_matches_for_glob(spec, "rubygems_plugin#{Bundler.rubygems.suffix_pattern}")
+        spec.matches_for_glob("rubygems_plugin#{Bundler.rubygems.suffix_pattern}")
       rescue TypeError
         error_message = "#{spec.name} #{spec.version} has an invalid gemspec"
         raise Gem::InvalidSpecificationException, error_message

lib/bundler/rubygems_integration.rb

@@ -70,14 +70,6 @@ module Bundler
       default
     end
 
-    def spec_matches_for_glob(spec, glob)
-      return spec.matches_for_glob(glob) if spec.respond_to?(:matches_for_glob)
-
-      spec.load_paths.flat_map do |lp|
-        Dir["#{lp}/#{glob}#{suffix_pattern}"]
-      end
-    end
-
     def stub_set_spec(stub, spec)
       stub.instance_variable_set(:@spec, spec)
     end