[codex] Release 0.2.3

[aviadr1]

Summary

• bump package version to 0.2.3
• date the changelog entry for the completed compatibility, docs, CI, release, and Dependabot hardening work
• refresh uv.lock package metadata to 0.2.3

Validation

• uv lock --check
• uv run ruff check .
• uv run ruff format --check .
• uv run pytest
• uv run python -m compileall -q src tests
• uv run --python 3.8 python -m py_compile src/winuvloop/__init__.py
• uv build
• uv run twine check dist/*