Fix pixi py-fmt-check not running ruff check (rerun-io#5995)

### What

Previously, you could pass ci without fixing all ruff lints - `pixi run
py-fmt` would fix them but `pixi run py-fmt-check` wouldn't complain.

Technically none of this is formatting, but we still put it under
formatting since most of it can be fixed automatically and it runs
blazingly fast (very much in contrast to `pixi run py-lint`), both of
which are more typical for formatting.

### Checklist
* [x] I have read and agree to [Contributor
Guide](https://github.com/rerun-io/rerun/blob/main/CONTRIBUTING.md) and
the [Code of
Conduct](https://github.com/rerun-io/rerun/blob/main/CODE_OF_CONDUCT.md)
* [x] I've included a screenshot or gif (if applicable)
* [x] I have tested the web demo (if applicable):
* Using examples from latest `main` build:
[rerun.io/viewer](https://rerun.io/viewer/pr/5995?manifest_url=https://app.rerun.io/version/main/examples_manifest.json)
* Using full set of examples from `nightly` build:
[rerun.io/viewer](https://rerun.io/viewer/pr/5995?manifest_url=https://app.rerun.io/version/nightly/examples_manifest.json)
* [x] The PR title and labels are set such as to maximize their
usefulness for the next release's CHANGELOG
* [x] If applicable, add a new check to the [release
checklist](https://github.com/rerun-io/rerun/blob/main/tests/python/release_checklist)!

- [PR Build Summary](https://build.rerun.io/pr/5995)
- [Recent benchmark results](https://build.rerun.io/graphs/crates.html)
- [Wasm size tracking](https://build.rerun.io/graphs/sizes.html)

To run all checks from `main`, comment on the PR with `@rerun-bot
full-check`.

pixi.toml

@@ -106,7 +106,7 @@ misc-fmt-check = "prettier --check '**/*.{yml,yaml,js,css,html}'"
 
 # Run first ruff fix, then ruff format, order is important see also https://twitter.com/charliermarsh/status/1717229721954799727
 py-fmt = "ruff check --fix --config rerun_py/pyproject.toml . && ruff format --config rerun_py/pyproject.toml ."
-py-fmt-check = "ruff format --check --config rerun_py/pyproject.toml"
+py-fmt-check = "ruff check --config rerun_py/pyproject.toml . && ruff format --check --config rerun_py/pyproject.toml"
 py-lint = "mypy --install-types --non-interactive --no-warn-unused-ignore"
 
 py-build = "maturin develop --manifest-path rerun_py/Cargo.toml --extras=tests"