Ignore dirty submodules

[adamdempsey90]

Background

I don't know why we didn't do this a long time ago. This will get rid of the submodules showing up in git status or git diff if there was no change to them other than any things that changed from building the code.

We could go one step further and do ignore = untracked to ignore untracked files that may have been added, but that sounds more dangerous.

Description of Changes

Checklist

• New features are documented
• Tests added for bug fixes and new features
• (@lanl.gov employees) Update copyright on changed files
• Any contribution that was created or modified with the assistance of generative AI must have a comment disclosing this such as // This file was created in part or in whole by generative AI

[RyanWollaeger]

LGTM - it looks like the indentation is a bit behind url - is this intentional?

[adamdempsey90]

LGTM - it looks like the indentation is a bit behind url - is this intentional?

The other lines were using \t and my new lines where using spaces. I've updated all lines to use spaces.