Refactor Stripe subscription line item management in WorkspaceUsersUpdated job

- Improve handling of extra user line items in Stripe subscriptions
- Add logic to remove line item when quantity is zero
- Optimize line item creation and update process
- Simplify environment check using app() helper method

api/app/Jobs/Billing/WorkspaceUsersUpdated.php

@@ -38,7 +38,7 @@ class WorkspaceUsersUpdated implements ShouldQueue
     public function handle(): void
     {
         // If self-hosted, no need to update billing
-        if (!pricing_enabled() || \App::environment('testing')) {
+        if (!pricing_enabled() || app()->environment('testing')) {
             return;
         }
 
@@ -80,18 +80,29 @@ class WorkspaceUsersUpdated implements ShouldQueue
         $subscriptionInterval = BillingHelper::getLineItemInterval($mainSubscriptionItem);
 
         $extraUserLineItem = $this->getLineItem($lineItems, 'extra_user');
+
+        if ($quantity === 0) {
+            // If quantity is 0, remove the line item if it exists
             if ($extraUserLineItem) {
+                $stripe->subscriptionItems->delete($extraUserLineItem->id);
+            }
+        } else {
+            // If quantity is greater than 0
+            if ($extraUserLineItem) {
+                // Update existing line item
                 $stripe->subscriptionItems->update(
                     $extraUserLineItem->id,
                     ['quantity' => $quantity]
                 );
             } else {
+                // Create new line item
                 $stripeSub->items->create([
                     'price' => $extraUserPricing[$subscriptionInterval],
                     'quantity' => $quantity,
                 ]);
             }
         }
+    }
 
     private function getLineItem(Collection $lineItems, string $productName)
     {