Update with-sam.ts

Author: iliapolo

packages/@aws-cdk-testing/cli-integ/lib/with-sam.ts

@@ -35,6 +35,7 @@ export function withSamIntegrationCdkApp<A extends TestContext & AwsContext>(blo
       context.output,
       context.aws,
       context.randomString);
+    await fixture.ecrPublicLogin();
 
     let success = true;
     try {