Missing dependency and outdated README

[IdrisB23]

Branch: main
README.md for the github-agent sample samples/python/agents/github-agent is outdated:

uv run . http://localhost:10007
> Using CPython 3.13.9                                                                                                                                                                                        
> Creating virtual environment at: ...
>       Built a2a-sample-client-cli ...
> Usage: . [OPTIONS]                                                                                                                                                                                          
> Try '. --help' for help.                                                                                                                                                                                                                                                                                                                                                                                                > Error: Got unexpected extra argument (http://localhost:10007)

Missing dependency: fastapi

class A2AFastAPI(FastAPI):
raise TypeError(f"Cannot subclass {self!r}") TypeError: Cannot subclass typing.Any
in .venv\lib\site-packages\a2a\server\apps\jsonrpc\fastapi_app.py", line 28

Culprit

try:
    from fastapi import FastAPI
    _package_fastapi_installed = True
except ImportError:
    FastAPI = Any # missing dependency is harder to debug this way!
    _package_fastapi_installed = False