fix(it): remove externalId IT tests — externalId is now server-derived (LLMO-5566)

Mirrors the unit test fix: externalId is no longer accepted from the client
(it is derived server-side from the site's IMS org id), so the IT tests that
expected a 400 for a missing externalId are removed for both log-delivery and
log-rescan.

Introduced by: N/A
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: cboldis

test/it/shared/tests/llmo-cloudfront-log-delivery.js

@@ -106,19 +106,9 @@ export default function llmoCloudFrontLogDeliveryTests(getHttpClient, resetData)
         expect(res.status).to.equal(400);
       });
 
-      it('returns 400 when externalId is missing', async () => {
-        const http = getHttpClient();
-        const res = await http.llmoAdmin.post(path, {
-          accountId: VALID_ACCOUNT_ID, distributionId: VALID_DISTRIBUTION_ID,
-        });
-        expect(res.status).to.equal(400);
-      });
-
       it('returns 400 when distributionId is missing', async () => {
         const http = getHttpClient();
-        const res = await http.llmoAdmin.post(path, {
-          accountId: VALID_ACCOUNT_ID, externalId: VALID_EXTERNAL_ID,
-        });
+        const res = await http.llmoAdmin.post(path, { accountId: VALID_ACCOUNT_ID });
         expect(res.status).to.equal(400);
       });
 
@@ -141,12 +131,6 @@ export default function llmoCloudFrontLogDeliveryTests(getHttpClient, resetData)
         });
         expect(res.status).to.equal(400);
       });
-
-      it('returns 400 when externalId is missing', async () => {
-        const http = getHttpClient();
-        const res = await http.llmoAdmin.post(path, { accountId: VALID_ACCOUNT_ID });
-        expect(res.status).to.equal(400);
-      });
     });
   });
 }