Fix ctx.time() ValueError for built-in time.time

[sachinbehera-punt]

Fix ctx.time() ValueError by wrapping time.time in a lambda

• Replaced direct call to built-in time.time with a lambda in server_context.py
• Prevents inspect.signature error for built-in functions when using ctx.run_typed

[github-actions]

All contributors have signed the CLA ✍️ ✅
_{Posted by the CLA Assistant Lite bot.}

[sachinbehera-punt]

I have read the CLA Document and I hereby sign the CLA

[sachinbehera-punt]

Error Message

`A retry-able error was received from the service while processing the invocation.

[500 Internal] ValueError('no signature found for builtin ')
Traceback (most recent call last):

File "/data/backend/.venv/lib/python3.12/site-packages/restate/server_context.py", line 304, in enter
out_buffer = await invoke_handler(handler=self.handler, ctx=self, in_buffer=in_buffer)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

File "/data/backend/.venv/lib/python3.12/site-packages/restate/handler.py", line 241, in invoke_handler
out_arg = await handler.fn(ctx) # type: ignore [call-arg]
^^^^^^^^^^^^^^^^^^^^^

File "/data/backend/api/restate_workflows/daily_crawl_workflow.py", line 39, in run
start_time = await ctx.time()
^^^^^^^^^^

File "/data/backend/.venv/lib/python3.12/site-packages/restate/server_context.py", line 504, in time
return self.run_typed("timestamp", time.time)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

File "/data/backend/.venv/lib/python3.12/site-packages/restate/server_context.py", line 584, in run_typed
signature = inspect.signature(action, eval_str=True)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

File "/home/ubuntu/.local/share/uv/python/cpython-3.12.11-linux-x86_64-gnu/lib/python3.12/inspect.py", line 3348, in signature
return Signature.from_callable(obj, follow_wrapped=follow_wrapped,
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

File "/home/ubuntu/.local/share/uv/python/cpython-3.12.11-linux-x86_64-gnu/lib/python3.12/inspect.py", line 3085, in from_callable
return _signature_from_callable(obj, sigcls=cls,
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

File "/home/ubuntu/.local/share/uv/python/cpython-3.12.11-linux-x86_64-gnu/lib/python3.12/inspect.py", line 2602, in _signature_from_callable
return _signature_from_builtin(sigcls, obj,
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

File "/home/ubuntu/.local/share/uv/python/cpython-3.12.11-linux-x86_64-gnu/lib/python3.12/inspect.py", line 2392, in _signature_from_builtin
raise ValueError("no signature found for builtin {!r}".format(func))

ValueError: no signature found for builtin `

[slinkydeveloper]

Thanks for the contribution, I'm finishing this here #138