fix: add date picker placeholder for Norwegian Bokmål

[16patsle]

Closes #8593

✅ Pull Request Checklist:

• Included link to corresponding React Spectrum GitHub Issue.
• Added/updated unit tests and storybook for this change (for new code or code which already has tests).
• Filled out test instructions.
• Updated documentation (if it already exists for this component).
• Looked at the Accessibility Practices for this feature - Aria Practices

📝 Test Instructions:

Testing a date picker with the locale set to "nb-NO" should produce the same placeholder as "nn-NO", that is "dd.mm.åååå".

🧢 Your Project:

[16patsle]

It feels a bit silly for a change that's copy-paste and change a single letter, but I guess I can get the CLA sorted out too

[snowystinger]

If you cannot sign the CLA, let us know so we can open our own PR for it. I agree it's a bit silly for something so small, especially since there is no other way to do it, but alas, I do not make the rules for this :-/