refactor: simplify user signup view

- Remove unnecessary turbo frame tag from the signup form
- Directly render the form within the column div

This change simplifies the user signup view by removing the
unneeded turbo frame, which was not contributing to the
functionality. The form is now rendered directly, making the
code cleaner and easier to understand.

app/controllers/sessions_controller.rb

@@ -1,6 +1,7 @@
 class SessionsController < ApplicationController
   include SessionsHelper
   def new
+
   end
 
   def create

app/views/users/new.html.erb

@@ -4,8 +4,6 @@
 
 <div class="row">
   <div class="col-md-6 col-md-offset-3">
-    <%= turbo_frame_tag "signup_form" do %>
-      <%= render 'form' %>
-    <% end %>
+    <%= render 'form' %>
   </div>
 </div>