MAINT: Ignore config files from file explorers

[david-cortes-intel]

Description

This PR updates the .gitignore file to ignore custom configurations from file explorers which are left in the directories where they apply.

Checklist to comply with before moving PR from draft:

PR completeness and readability

• I have reviewed my changes thoroughly before submitting this pull request.
• Git commit message contains an appropriate signed-off-by string (see CONTRIBUTING.md for details).
• I have added a respective label(s) to PR if I have a permission for that.
• I have resolved any merge conflicts that might occur with the base branch.

Testing

• I have run it locally and tested the changes extensively.

Performance

Not applicable.

[icfaust]

looks good to me