Add test setup to increase abortSignal max listeners

Prevent MaxListenersExceededWarning during high-concurrency batch tests by increasing the listener limit from 10 to 50.

Author: jdalton

test/utils/setup.mts

@@ -0,0 +1,8 @@
+/** @fileoverview Vitest setup file for test utilities. */
+import events from 'node:events'
+
+import abortSignal from '@socketsecurity/registry/lib/constants/abort-signal'
+
+// Increase max listeners for abortSignal to prevent warnings during high-concurrency tests.
+// The batchPackageStream method can add many concurrent abort listeners.
+events.setMaxListeners(50, abortSignal)