Modify PyPA classifiers and Shields.io badge URLs (#6082)
## Summary
Updated `pyproject.toml` classifiers from `"Development Status :: 4 -
Beta"` to `"Development Status :: 5 - Production/Stable"` to reflect the
transition from Beta to Full Release.
Updated the `README.md` to use `.com/astral-sh/ruff/...` instead of
`.com/charliermarsh/ruff/...` in Shields.io badges to reflect the
transition to a company.
## Test Plan
Utilized the official PyPA classifiers list (located at:
https://pypi.org/classifiers/)
Previewed the markdown file in different browsers on Github to ensure
all badges and logos still render properly.
