Add OS X metadata files starting with ._ to .gitignore

It came up in !38184 (comment 3954681) and seems to be a good idea to ignore these, similarly to other files of this kind we already have in the list.

Tagging @emoyse, @elmsheus, @smh

Change submitted from GitLab web editor

I strongly support this!

added master review-pending-level-1 labels

Verified with find . -name '._*' that there are no such files committed to athena. Ready to be approved once CI finishes. -- L1

CI Result FAILURE (hash c5aece95)

	Athena	AthSimulation	AthGeneration	AnalysisBase
externals
cmake
make
required tests
optional tests

Full details available on this CI monitor view
Athena: number of compilation errors 0, warnings 0
AthSimulation: number of compilation errors 0, warnings 0
AthGeneration: number of compilation errors 0, warnings 0
AnalysisBase: number of compilation errors 0, warnings 0
For experts only: Jenkins output [CI-MERGE-REQUEST-CC7 23408]

Looks like the "CI Result FAILURE" output is wrong, approving (L1).

added review-approved label and removed review-pending-level-1 label

Sorry I didn't notice this was a git modification @rbielski is this related to this

10:25:23 11:25:23 DEBUG      affected domains:
10:25:23                     - 
10:25:23 11:25:23 DEBUG      unmapped files:
10:25:23                     - .gitignore
10:25:23 11:25:23 DEBUG      no responsible domain found -> please check that this is expected
10:25:23 Traceback (most recent call last):
10:25:23   File "/var/lib/jenkins/workspace/scripts/CI/handle_new_mr.py", line 262, in <module>
10:25:23     main()
10:25:23   File "/var/lib/jenkins/workspace/scripts/CI/handle_new_mr.py", line 259, in main
10:25:23     handle_new_merge_request(args)
10:25:23   File "/var/lib/jenkins/workspace/scripts/CI/handle_new_mr.py", line 197, in handle_new_merge_request
10:25:23     comment += warn_unmapped_files(unmapped_files)
10:25:23   File "/var/lib/jenkins/workspace/scripts/CI/handle_new_mr.py", line 78, in warn_unmapped_files
10:25:23     for p in filess:
10:25:23 NameError: global name 'filess' is not defined
10:25:23 Build step 'Execute shell' marked build as failure
10:25:24 Finished: FAILURE

added review-user-action-required label and removed review-approved label

I think this is nothing to worry about but just checking.

Looks like a typo in the CI script itself: https://gitlab.cern.ch/atlas-sit/CI/-/blob/master/handle_new_mr.py#L78 i.e. filess instead of files

no responsible domain found -> please check that this is expected

Yes, this part is 100% expected. The .gitignore file doesn't belong to any software domain and this is fine.

However, the fact that the script actually crashes on this is not fine. Indeed looks like a simple typo, so hopefully trivial for @aundrus to fix.

Thanks for correct diagnostics. I corrected the typo: filess->files. I restarted the CI job for this MR to make sure that it works OK (although it is really a trivial typo)

added review-approved label and removed review-user-action-required label

merged

mentioned in commit 944f8ea6

added sweep:ignore label