``test_pgmq_bus_lazy_import`` and ``test_redis_bus_lazy_import``
import ``pipecat.bus.network.pgmq`` / ``redis`` directly, which raises
when the optional ``pgmq`` / ``redis`` packages are missing. Gate each
test with ``@unittest.skipUnless`` on a top-level probe of the
underlying package so they're skipped (not errored) in environments
without the extras. ``test_unknown_attribute_raises`` is unaffected.
Brings over 215 tests across 15 files covering the new
multi-task framework: BaseTask / PipelineTask bus lifecycle,
job RPC and job groups, the bus message hierarchy and serializers,
TaskBus + AsyncQueueBus + RedisBus + PgmqBus (with direct and
isolated backends), TaskRegistry, the BusBridgeProcessor, the
WebSocket proxy tasks, the LLMTask deferral logic, and the
PipelineRunner spawn-and-attach flow.
