Fix race condition in SequenceToPaginatedResponseAdapter timeout eviction

[fscarponi]

Problem

SequenceToPaginatedResponseAdapter had a race condition in cursor eviction. When a new cursor was created, the timeout job was launched immediately via launch { ... }, but the cursor was stored in the map only after the launch. With very short orphanedIteratorsEvictionTimeout values, the timeout job could fire and call map.remove(cursor) before map.put(cursor, ...) had executed. This left the cursor permanently in the map with no eviction job, effectively leaking the iterator.

Fix

Changed the timeout job to use CoroutineStart.LAZY so it is created but not started until after the cursor is stored in the map. The job is then explicitly started with timeoutJob.start(), guaranteeing the correct ordering:

1. Create timeout job (lazy, does not run yet)
2. Store cursor + iterator + job in the map
3. Start the timeout job

This eliminates the race condition regardless of how short the eviction timeout is