Exclude magic comments from documentation

This commit ensures magic comments are excluded from documentation. They
were already filtered out when eagerly indexing comments but the same
logic wasn't applied when lazily loading comments.

Author: thomasmarshall

lib/ruby_indexer/lib/ruby_indexer/entry.rb

@@ -86,7 +86,7 @@ def comments
           correct_group.filter_map do |comment|
             content = comment.slice.chomp
 
-            if content.valid_encoding?
+            if content.valid_encoding? && !content.match?(@configuration.magic_comment_regex)
               content.delete_prefix!("#")
               content.delete_prefix!(" ")
               content

lib/ruby_indexer/test/classes_and_modules_test.rb

@@ -766,5 +766,25 @@ class Foo
         FileUtils.rm(path)
       end
     end
+
+    def test_lazy_comments_ignores_magic_comments
+      path = File.join(Dir.pwd, "lib", "foo.rb")
+      source = <<~RUBY
+        # frozen_string_literal: true
+
+        class Foo
+        end
+      RUBY
+      File.write(path, source)
+      @index.index_single(URI::Generic.from_path(path: path), source, collect_comments: false)
+
+      entry = @index["Foo"]&.first #: as !nil
+
+      begin
+        assert_empty(entry.comments)
+      ensure
+        FileUtils.rm(path)
+      end
+    end
   end
 end