We were passing 'false' to --export-metadata-files, but it was
considered True (non-zero length string), and the metadata was
always included in the export.
Co-authored-by: Marius van den Beek <m.vandenbeek@gmail.com>
ruff (https://github.com/charliermarsh/ruff) is a new and extremely fast
Python linter, written in Rust.
Ruff can be used to replace Flake8 (plus a variety of plugins), isort,
pydocstyle, yesqa, eradicate, pyupgrade, and autoflake.
Here ruff is added to our current linters (flake8, flake8-bugbear and isort)
while we assess its reliability.
I've not enabled the isort rules because many of the options we use are not
implemented yet. I have instead enabled the pyupgrade rules (a tool which I
run manually every few months).
Also:
- Fix new linting errors reported by ruff.
