feat(queue): add unique job deduplication support

[romanstingler]

In CloudTasksQueue.php, the taskName() method unconditionally prepended a Str::ulid() to every task name, which bypassed Laravel's uniqueFor/uniqueId() mechanism. This caused duplicate tasks because Cloud Tasks saw each dispatch as a unique task name, even when the underlying job was the same.

Changes made:
taskName() method (line 240-259): Now checks if the job is a unique job via isUniqueJob(), meaning it has a uniqueId() method and a truthy uniqueFor property. If so, $job->uniqueId() is used as the task name without the ULID prefix. Non-unique jobs retain the original ULID-prefixed behavior.

pushToCloudTasks() method (line 222-232): Wraps CloudTasksApi::createTask() in a try-catch for ApiException. If the error is a 409 (ALREADY_EXISTS) and the job is unique, the exception is swallowed and the existing UUID is returned, matching Laravel's expected unique job behavior where dispatching a duplicate is a no-op.

isUniqueJob() helper (line 262-268): Extracted the duck-typing check into a single private method to avoid duplication between taskName() and pushToCloudTasks().

With this fix, a HandleOrder job with uniqueFor = 3600 and uniqueId() returning Handle-Order-10-11479956619529 will now create task names like:

projects/.../tasks/Handle-Order-10-11479956619529
Instead of the previous behavior:

projects/.../tasks/01KQWQQPH0902D52ERCJMEE872-Handle-Order-10-11479956619529

Cloud Tasks will reject duplicates with ALREADY_EXISTS, preventing multiple identical tasks from being queued.