Fix float32 JSON serialization

[serareif]

Fix Error:

Traceback (most recent call last):
  File "/home/vscode/.local/lib/python3.10/site-packages/shiny/session/_session.py", line 665, in _run
    await flush()
  File "/home/vscode/.local/lib/python3.10/site-packages/shiny/reactive/_core.py", line 260, in flush
    await _reactive_environment.flush()
  File "/home/vscode/.local/lib/python3.10/site-packages/shiny/reactive/_core.py", line 178, in flush
    await self._flushed_callbacks.invoke()
  File "/home/vscode/.local/lib/python3.10/site-packages/shiny/_utils.py", line 528, in invoke
    await fn()
  File "/home/vscode/.local/lib/python3.10/site-packages/shiny/session/_session.py", line 1021, in _flush
    await self._send_message(message)
  File "/home/vscode/.local/lib/python3.10/site-packages/shiny/session/_session.py", line 960, in _send_message
    message_str: str = json.dumps(message) + "\n"
  File "/usr/local/lib/python3.10/json/__init__.py", line 231, in dumps
    return _default_encoder.encode(obj)
  File "/usr/local/lib/python3.10/json/encoder.py", line 199, in encode
    chunks = self.iterencode(o, _one_shot=True)
  File "/usr/local/lib/python3.10/json/encoder.py", line 257, in iterencode
    return _iterencode(o, 0)
  File "/usr/local/lib/python3.10/json/encoder.py", line 179, in default
    raise TypeError(f'Object of type {o.__class__.__name__} '
TypeError: Object of type float32 is not JSON serializable
**Object of type float32 is not JSON serializable**

The issue was resolved by globally converting all possible numerical values into a format that is compatible with JSON. This ensures that both existing and future values are always JSON-serializable, preventing any non-JSON-compatible values from causing errors.

[nictru]

The proposed solution is a symptomatic solution rather than a root-cause solution. I understand the problem only occurs in some AnnData objects; otherwise, we would have noticed it during earlier testing. This means that the structural differences should be solvable by converting the datatypes already when reading the input.

I understand that the monkey-patching looks rather elegant, but since json.dumps is a core functionality in networking, there might be negative side effects that we are unaware of - potentially just shifting the problem from one location to the other. Thus, I would not be comfortable merging this solution.

[serareif]

"I understand the problem only occurs in some AnnData objects; otherwise, we would have noticed it during earlier testing"
The problem occurs in all of the AnnData object which we used before for testing too. It also occurs in the commits beforehand for the same AnnData objects, which worked well before.
I will try to fix the issue by converting the datatypes beforehand.