Re-activate e2e tests for the shortcode split UPE (#5591)

Co-authored-by: Timur Karimov <[email protected]>

Author: timur27

changelog/reenable-split-upe-e2e-tests

@@ -0,0 +1,4 @@
+Significance: patch
+Type: fix
+
+Re-enable split UPE E2E tests and ensure they pass.

tests/e2e/specs/upe-split/shopper/shopper-upe-enabled-all-flows.spec.js

@@ -36,14 +36,11 @@ describe( 'Enabled Split UPE', () => {
 		await merchant.logout();
 	} );
 
-	// the tests are a bit flakey, so disabling for now.
-	describe.skip( 'Shortcode checkout', () => {
+	describe( 'Shortcode checkout', () => {
 		it( 'should save the card', async () => {
 			await setupProductCheckout(
 				config.get( 'addresses.customer.billing' )
 			);
-			await shopper.goToCheckout();
-			await uiUnblocked();
 			await shopperWCP.selectNewPaymentMethod();
 			await fillCardDetails( page, card );
 			await shopperWCP.toggleSavePaymentMethod();