Auto merge of #82340 - kennytm:fix-82254, r=Mark-Simulacrum

Auto merge of #82340 - kennytm:fix-82254, r=Mark-Simulacrum

Fix some Python2→3 error in publish_toolstate.py

Fix #82254.

The error is primarily due to `data = json.dumps(…)` producing a `str` instead of a `bytes`, which are different types on Python 3. But then `urllib.request.urlopen(…, data)` cannot accept `data` as a `str`, thus the error.

This PR added `.encode()` call after `json.dumps()` to ensure we are sending `bytes`. Additionally, we added type annotation to ensure things can statically type-check with `mypy` on both Python 2 and 3.