Update oauth logic to account for new admin-web url

Author: jecepeda

lib/shopify_api/auth/oauth.rb

@@ -114,8 +114,9 @@ def auth_base_uri(shop)
           return "https://#{shop}/admin" unless defined?(DevServer) && shop.include?(".my.shop.dev")
 
           # For first-party apps in development only, we leverage DevServer to build the admin base URI
-          admin_web = T.unsafe(Object.const_get("DevServer")).new("web") # rubocop:disable Sorbet/ConstantsFromStrings
-          admin_host = admin_web.host!(nonstandard_host_prefix: "admin")
+          admin_web = T.unsafe(Object.const_get("DevServer")) # rubocop:disable Sorbet/ConstantsFromStrings
+            .new("admin-web")
+          admin_host = admin_web.host!
           shop_name = shop.split(".").first
 
           "https://#{admin_host}/store/#{shop_name}"