Remove unnecessary packer_type template variable

The template file already uses hardcoded 'shakapacker' values,
so no need to pass the variable anymore.

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <[email protected]>

Author: justin808

lib/generators/react_on_rails/base_generator.rb

@@ -41,7 +41,7 @@ def copy_base_files
         base_templates = %w[config/initializers/react_on_rails.rb]
         base_files.each { |file| copy_file("#{base_path}#{file}", file) }
         base_templates.each do |file|
-          template("#{base_path}/#{file}.tt", file, { packer_type: "shakapacker" })
+          template("#{base_path}/#{file}.tt", file)
         end
       end