test: deflake indexed e2e (#11911)

### What?
This PR aims to deflake the indexed fields e2e test in
`test/fields/collections/Indexed/e2e.spec.ts`.

The issue is that this test is setup in a way where sometimes two toasts
will present themselves in the ui. The second toast assertion will fail
with a strict mode violation as the toast locator will resolve to two
elements.

### Why?
To prevent this test from flaking in ci.

### How?
Adding a new `dismissAfterAssertion` flag to the `assertToastErrors`
helper function which dismisses the toasts. This way, the toasts will
not raise the aforementioned error as they will be dismissed from the
ui.

The logic is handled in a separate loop through such that the assertions
occur first. This is done so that dismissing a toast does not surface
errors due to the order of toasts being shown changing.

test/helpers/assertToastErrors.ts

@@ -5,7 +5,9 @@ import { expect } from '@playwright/test'
 export async function assertToastErrors({
   page,
   errors,
+  dismissAfterAssertion,
 }: {
+  dismissAfterAssertion?: boolean
   errors: string[]
   page: Page
 }): Promise<void> {
@@ -24,4 +26,13 @@ export async function assertToastErrors({
       ).toHaveText(error)
     }
   }
+
+  if (dismissAfterAssertion) {
+    const closeButtons = page.locator('.payload-toast-container button.payload-toast-close-button')
+    const count = await closeButtons.count()
+
+    for (let i = 0; i < count; i++) {
+      await closeButtons.nth(i).click()
+    }
+  }
 }