non-development work is a subset of toxic work environments?

No. I don't think so. Depends on how you identify development work. Is documentation, test-writing, requirements gathering, planning, backlog grooming, educating, or advocating considered non-development work? (I think all that stuff pretty clearly falls under the purview of 'developer', but I've gotten a lot of feedback from folks over the years who think it's not.)

Toxic work environment can include things like sexual harassment, micro and macro aggressions, offensive language (I had a manager for a while who called his reports 'motherfuckers), etc. I wouldn't normally consider non-development work to be 'toxic' in the same way I'd consider, say, working with someone who consistently talks down to women and minorities.

To add onto your comment - I'd also consider a work environment that automatically assigns the documentation, test-writing, etc. to a gender minority (or other minority) to be toxic.

No, there is some overlap, but most non-development tasks are not really toxic, just overhead.

I have to interview other developers. This is not a part of a toxic work environment (in fact it can prevent them).

Toxic work environment be entirely development, for instance if they put your computer in the bathroom I'd call that toxic.

I suspect most females mean some form of sexual harassment is tolerated. This is a big problem that men tend to culturally ignore.

No. Software development for any non-trivial project requires more than just slapping a few requirements down on paper and then flinging code into an editor.