Add `RUFF_OUTPUT_FILE` environment variable support (#10992)
## Summary
I've added support for configuring the `ruff check` output file via the
environment variable `RUFF_OUTPUT_FILE` akin to #1731.
This is super useful when, e.g., generating a [GitLab code quality
report](https://docs.gitlab.com/ee/ci/testing/code_quality.html#implement-a-custom-tool)
while running Ruff as a pre-commit hook. Usually, `ruff check` should
print its human-readable output to `stdout`, but when run through
`pre-commit` _in a GitLab CI job_ it should write its output in `gitlab`
format to a file. So, to override these two settings only during CI,
environment variables come handy, and `RUFF_OUTPUT_FORMAT` already
exists but `RUFF_OUTPUT_FILE` has been missing.
A (simplified) GitLab CI job config for this scenario might look like
this:
```yaml
pre-commit:
stage: test
image: python
variables:
RUFF_OUTPUT_FILE: gl-code-quality-report.json
RUFF_OUTPUT_FORMAT: gitlab
before_script:
- pip install pre-commit
script:
- pre-commit run --all-files --show-diff-on-failure
artifacts:
reports:
codequality: gl-code-quality-report.json
```
## Test Plan
I tested it manually.
