Fix type errors in runner and add to pyright checked set

Make required parameters non-optional: LiveKitRunnerArguments.token,
_create_telephony_transport args. Use os.environ[] instead of
os.getenv() for required WhatsApp env vars. Guard spec/loader None
in module loading. Tighten sip_caller_phone guard in daily.py.

pyrightconfig.json

@@ -10,7 +10,8 @@
     "src/pipecat/observers",
     "src/pipecat/extensions",
     "src/pipecat/turns",
-    "src/pipecat/pipeline"
+    "src/pipecat/pipeline",
+    "src/pipecat/runner"
   ],
   "exclude": [
     "**/*_pb2.py",