chore(integrations): remove defunct langgraph-python-threads example (ENT-800)

The standalone threads template is retired: the ENT-679 rollout was
reverted from main (CopilotKit#5215/CopilotKit#5216/CopilotKit#5217) and the settled model is base
langgraph-python + Intelligence activation overlay. The Intelligence
CLI (main and published copilotkit@3.0.2) no longer references it.

Also drops its two entries from .github/config-allowlist.txt.

Author: BenTaylorDev

.github/config-allowlist.txt

@@ -17,8 +17,6 @@ examples/integrations/crewai-crews/next.config.ts
 examples/integrations/crewai-flows/next.config.ts
 examples/integrations/langgraph-fastapi/next.config.ts
 examples/integrations/langgraph-js/next.config.ts
-examples/integrations/langgraph-python-threads/apps/app/src/vite-env.d.ts
-examples/integrations/langgraph-python-threads/apps/app/vite.config.ts
 examples/integrations/langgraph-python/next.config.ts
 examples/integrations/llamaindex/next.config.ts
 examples/integrations/mastra/next.config.ts