refactor: remove SSO settings page; consolidate SSO identity management under Security settings

- Removed the `Settings::SsoIdentitiesController` and views for a simplified user experience.
- Moved SSO identity management to the Security settings page (`Settings::SecuritiesController`).
- Updated locale keys and layout for the new structure.
- Fixed unlink protection warnings and adjusted redirection path.
- Cleaned up routes, helper methods, and redundant code.

app/components/UI/account/activity_feed.html.erb

@@ -77,7 +77,7 @@
           <div class="pl-0.5 col-span-8 flex items-center gap-4">
             <%= check_box_tag "selection_entry",
                               class: "checkbox checkbox--light hidden lg:block",
-                              data: { 
+                              data: {
                                 action: "bulk-select#togglePageSelection",
                                 checkbox_toggle_target: "selectionEntry"
                               } %>