test(executor): remove stale fire-and-forget assertion

The deleted test asserted wrappedOnBlockStart returns before the user
callback resolves. After the Stage 1 drain refactor, wrappedOnBlockStart
must await the user callback so the executor's trackCallback set covers
SSE writes — otherwise the drain at terminal-event time can't guarantee
block:* flushes before execution:*.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

Author: waleedlatif1

apps/sim/lib/workflows/executor/execution-core.test.ts

@@ -239,37 +239,6 @@ describe('executeWorkflowCore terminal finalization sequencing', () => {
     expect(findStartBlockMock).toHaveBeenCalledWith(expect.anything(), 'external', false)
   })
 
-  it('does not await user block start callback after persistence completes', async () => {
-    let releaseCallback: (() => void) | undefined
-    const callbackPromise = new Promise<void>((resolve) => {
-      releaseCallback = resolve
-    })
-
-    executorExecuteMock.mockResolvedValue({
-      success: true,
-      status: 'completed',
-      output: { done: true },
-      logs: [],
-      metadata: { duration: 123, startTime: 'start', endTime: 'end' },
-    })
-
-    await executeWorkflowCore({
-      snapshot: createSnapshot() as any,
-      callbacks: {
-        onBlockStart: vi.fn(() => callbackPromise),
-      },
-      loggingSession: loggingSession as any,
-    })
-
-    const contextExtensions = executorConstructorMock.mock.calls[0]?.[0]?.contextExtensions
-
-    await expect(
-      contextExtensions.onBlockStart('block-1', 'Fetch', 'api', 1)
-    ).resolves.toBeUndefined()
-
-    releaseCallback?.()
-  })
-
   it('awaits terminal completion before updating run counts and returning', async () => {
     const callOrder: string[] = []