Simplify normalization of the delimiter

I found the `split` can take in a regular expression.

lib/importmap/packager.rb

@@ -70,9 +70,7 @@ def pin_options_for_package(package)
 
     return {} if raw_options.blank?
 
-    normalized_delimiter_raw_options = raw_options[:pin_options].gsub(/,\s/, ',').split(',')
-
-    normalized_delimiter_raw_options.each_with_object({}) do |option, hash|
+    raw_options[:pin_options].split(/,\s|,/).each_with_object({}) do |option, hash|
       match_data = option.match(/^(?<option_name>[^:]*):[\s+]?["']?(?<option_value>.*[^"'])["']?$/)
 
       hash[match_data[:option_name]] = cast_option_value(match_data[:option_value])