fix(webapp): a replayed run keeps its original gate set, empty included

Passing undefined for a gateless original fell back to the task's
current gates, so old runs replayed after new limits were added would
silently gain them.

Author: matt-aitken

apps/webapp/app/v3/services/replayTaskRun.server.ts

@@ -144,7 +144,7 @@ export class ReplayTaskRunService extends BaseService {
               overrideOptions.concurrencyKey ?? existingTaskRun.concurrencyKey ?? undefined,
             gates: Array.isArray(existingTaskRun.gates)
               ? (existingTaskRun.gates as Array<{ queue: string; concurrencyKey?: string }>)
-              : undefined,
+              : [],
             maxAttempts: overrideOptions.maxAttempts,
             maxDuration: overrideOptions.maxDurationSeconds,
             machine: