Investigate .gitgnore issues

[Witchblade101]

Lots of hidden files and folders were included in a recent PR, including "._" files that are explicitly included in our .gitignore file. Investigate what changes are needed to stop that from happening in the future.

Any reason to not ignore all '.' files, instead of calling out specific ones like we do now?

[mgennaro]

I note that in PRs #252 and #254 (both? one? I don't recall), I did git rm a huge bunch of NIRSpec files in the pre_delivery area, which I was indeed surprise to have to deal with

[mgennaro]

But actually now taht I looked, the .gitignore file does NOT exclude the pre_delivery folder. Exclduing that has been my automatic behavior in the past (ie I never git add * or git add files_in_the_pre_delivery_data_folder), but someone must have done that for NIRSpec, and the thing got merged w/o removing those files from the PR.

[Witchblade101]

Deleting all of the files in pre_delivery and temporary_data is part of the release process. This is the first time we've had multiple instruments going into a release, due to all the SI commissioning going on at the same time. So nobody was starting from a clean slate, as was the usual.