Parametrize DIRAC group

[Bilokin]

Hi @meliache,

recently, the group policy in gbasf2 was diversified, so the users can now submit the jobs from different DIRAC groups, which have different queue priorities.
And since there was created a group belle_systematics we would like to add the corresponding functionality to the b2luigi, which is extremely useful for the systematics framework.
To submit a project from a group other than belle, one has to do the following:

• Create proxy with the custom group
• Add a custom path to the gbasf2 command via --output_path
• Project download should be done with the same custom DIRAC group
• The project name should be explicitly appended to the temporary download path, because it is not added by default for a custom group

In this PR I added two optional b2luigi parameters, gbasf2_proxy_group and gbasf2_project_lpn_path.
The latter one is required if the first one is supplied.

[meliache]

Cool, thanks 🙏. Just looking from my phone this looks good to me. I suggest also documenting this in the class comment for the Gbasf2Process at the top of the file, somewhere there is a listing of the important settings for gbasf2 and this will appear on the online sphinx docs. And also add this to the changelog.md under the |Unpublished (meaning not to yet in a release) section. The latter I can also do as a maintainer.

[Bilokin]

Thanks, I wrote the docs and the entry in the changelog, I hope it is correct.
There is an issue with the workflow though and I have no clues about it. Can you take a look?

[Bilokin]

Hi @meliache, can you take a look at the github workflow issue and the PR in general?

[meliache]

Sorry @Bilokin, last week I just had no time to look at this because we were aiming for unblinding of our analysis for PRL, so I didn't look at this properly yet.

There is an issue with the workflow though and I have no clues about it. Can you take a look?

Yep, can take a look. Our github action runs the syntax- and style-checker flake8 as a precommit-hook and somehow that fails, but not due to your code but something with that hook. I hadn't seen that before, possibly it's not a mistake on your side, I will check.

[meliache]

The flake8 pre-commit hook seems to fail due to an incompatibility between flake8 v3.9, which was set in the pre-commit config, and importlib_metadata version 5. I found this by googling as python/importlib_metadata#406. I created a PR which upgrades the pre-commit flake8 version to the latest version in #176. This will hopefully fix this issue. If not, I might need to further set importlib_metadata < 5.0.0 in the github action configuration