* rebuilding executor
* removing langchain
* Making all tests good
* fixing types and adding ability for nor using system prompts
* improving types
* pleasing the types gods
* pleasing the types gods
* fixing parser, tools and executor
* making sure all tests pass
* final pass
* fixing type
* Updating Docs
* preparing to cut new version
* fixed bug for manager overriding task agent and then added pydanic valditors to sequential when no agent is added to task
* better test and fixed task.agent logic
* fixed tests and better validator message
* added validator for async_execution true in tasks whenever in hierarchical run
