[rubyforgood#5777] Remove leave url for back navigation on first step…

… until guidance from developers/product

app/views/case_contacts/form/details.html.erb

@@ -1,6 +1,6 @@
 <div>
   <%= form_with(model: @case_contact, url: wizard_path(nil, case_contact_id: @case_contact.id), local: true, id: "casa-contact-form", class: "component-validated-form") do |form| %>
-    <%= render(Form::TitleComponent.new(title: @case_contact.decorate.form_title, subtitle: "Contact details", step: @page, total_steps: @total_pages, navigable: Form::StepNavigationComponent.new(nav_back: leave_case_contacts_form_path, nav_next: next_wizard_path))) %>
+    <%= render(Form::TitleComponent.new(title: @case_contact.decorate.form_title, subtitle: "Contact details", step: @page, total_steps: @total_pages, navigable: Form::StepNavigationComponent.new(nav_back: nil, nav_next: next_wizard_path))) %>
     <%= render "/shared/error_messages", resource: @case_contact %>
 
     <div class="card-style-1 pl-25 mb-10">