How to address the ability to work with culturally diverse populations and on interdisciplinary teams in an academic job application?
Broadly, this can be addressed in (1) and (3) by specifically (re)writing portions of your resume and cover letter to highlight interdisciplinary work you've done and multicultural teams you've been a part of, and in (2) by asking your references to mention it in their conversations/letters.

More specifically:

While it's pretty obvious that most cover letters you send out will be at least somewhat specific to the each position, it may be less apparently that your resume can be the same. In this case, you'll want to modify your resume to highlight cross-disciplinary and multicultural work you've done at previous institutions. List bullet points that specifically call out researchers from other fields. Mention the nationalities of the colleagues with whom you've had a public collaboration. For both of these, it will look waaay better if you also list papers you've written or grants that were funded as a result of the collaboration; it will show that you can not only collaborate, but you can collaborate effectively.

For your references, you should mention that this position is something that the institution is asking to have called out, and request that they do so in their letters and conversations. This is as simple as it sounds; just speak to them and make sure they're aware of it. Hopefully they won't forget and all will be well.

Good luck!