Replace skypack.dev with jsdeliver

skypack has an outage.

Author: jcoyne

lib/generators/blacklight/assets/importmap_generator.rb

@@ -8,7 +8,7 @@ class ImportmapGenerator < Rails::Generators::Base
       def import_javascript_assets
         append_to_file 'config/importmap.rb' do
           <<~CONTENT
-            pin "@github/auto-complete-element", to: "https://cdn.skypack.dev/@github/auto-complete-element"
+            pin "@github/auto-complete-element", to: "https://cdn.jsdelivr.net/npm/@github/auto-complete-element@3.8.0/+esm"
             pin "@popperjs/core", to: "https://ga.jspm.io/npm:@popperjs/[email protected]/dist/umd/popper.min.js"
             pin "bootstrap", to: "https://ga.jspm.io/npm:bootstrap@#{(defined?(Bootstrap) && Bootstrap::VERSION) || '5.3.5'}/dist/js/bootstrap.js"
           CONTENT