[E2E - All] Fix E2E test race condition in dispute challenge save test (#11164)

Author: mgascam

changelog/fix-e2e-all-wc-7_7-merchant-save-dispute-without-evidence

@@ -0,0 +1,5 @@
+Significance: patch
+Type: dev
+Comment: E2E test-only change, no production code affected.
+
+

tests/e2e/specs/wcpay/merchant/merchant-disputes-respond.spec.ts

@@ -643,11 +643,6 @@ test.describe( 'Disputes > Respond to a dispute', () => {
 					hasText: 'Evidence saved!',
 				} )
 			).toBeVisible( { timeout: 10000 } );
-
-			// Sanity-check the field didn't reset visually before leaving the page
-			await expect(
-				merchantPage.getByLabel( 'PRODUCT DESCRIPTION' )
-			).toHaveValue( 'my product description' );
 		} );
 
 		await test.step( 'Go back to the payment details page', async () => {