Chore: [AEA-6529] -changed test id (#734)

## Summary

https://nhsd-jira.digital.nhs.uk/browse/AEA-6529

- Routine Change
updating a test id as we can now have multiple prescription ID error
messages

Author: jonathanwelch1-nhs

.grype.yaml

@@ -1,3 +1,5 @@
 ignore:
   # node - being upgraded to 24.14.1
   - vulnerability: CVE-2026-21710
+  # waiting on APIM to upgrade to a secure version on pytest NHSD-APIM
+  - vulnerability: GHSA-vfmq-68hx-4jfw

pages/search_for_a_prescription.py

@@ -15,7 +15,7 @@ def __init__(self, page: Page):
         self.basic_details_search_header = page.get_by_test_id("basic-details-search-heading")
         self.error_summary = page.get_by_test_id("error-summary")
 
-        self.prescription_id_error = page.get_by_test_id("prescription-id-error")
+        self.prescription_id_error = page.get_by_test_id("error-message-multiple")
         self.prescription_id_input = page.get_by_test_id("prescription-id-input")
         self.find_prescription_button = page.get_by_test_id("find-prescription-button")