Use Regexp#match? when MatchData is not required (#8427)

Merge pull request 8427

lib/jekyll/cleaner.rb

@@ -44,7 +44,7 @@ module Jekyll
       dirs = keep_dirs
 
       Utils.safe_glob(site.in_dest_dir, ["**", "*"], File::FNM_DOTMATCH).each do |file|
-        next if file =~ HIDDEN_FILE_REGEX || file =~ regex || dirs.include?(file)
+        next if HIDDEN_FILE_REGEX.match?(file) || regex.match?(file) || dirs.include?(file)
 
         files << file
       end