From the formatter progress CI logs:
```
2023-08-07T03:49:02.5178602Z + mkdir -p /home/runner/work/ruff/ruff/target/progress_projects
2023-08-07T03:49:02.5193474Z + '[' '!' -d /home/runner/work/ruff/ruff/target/progress_projects/build ']'
2023-08-07T03:49:02.5194228Z + '[' '!' -d /home/runner/work/ruff/ruff/target/progress_projects/django ']'
2023-08-07T03:49:02.5194966Z + git clone --filter=tree:0 https://github.com/django/django /home/runner/work/ruff/ruff/target/progress_projects/django
2023-08-07T03:49:02.5209260Z Cloning into '/home/runner/work/ruff/ruff/target/progress_projects/django'...
```
```
2023-08-07T03:51:17.4726088Z [2m2023-08-07T03:51:17.472404Z[0m [31mERROR[0m Failed /home/runner/work/ruff/ruff/target/progress_projects/build: no python files in ["/home/runner/work/ruff/ruff/target/progress_projects/build"]
```
Seems that build exists but is an empty cached folder. These changes
should fix this by a) checking for `.git` instead of just the folder
existing b) running the commit checkout unconditionally. The latter is
also important if we ever want to update the SHAs.
**Summary** Prompted by
https://github.com/astral-sh/ruff/pull/6257#issuecomment-1661308410, it
tried to make the ecosystem script output on failure better
understandable. All log messages are now written to a file, which is
printed on error. Running locally progress is still shown.
Looking through the log output i saw that we currently log syntax errors
in input, which is confusing because they aren't actual errors, but we
don't check that these files don't change due to parser regressions or
improvements. I added `--files-with-errors` to catch that.
**Test Plan** CI
