Well at least php has it, which is a JITed scripting language just like Python. Although saying php has it is wrong, it's just a special doc tag that the linters pick up. Which is exactly what I want for Python. The only other scripting language I'm very comfortable with is typescript, which can also support @throws via jsdoc and eslint.

So to answer your question, I don't know if it's common, but from my minimal sample pool it's at least not unheard of.

You may not know this (just guessing because you commented on the nature of scripting/interpreted languages) but static analysis of dynamic languages has come really far and is an indispensable part of any reasonably sized project written in them these days. That's another reason why I'm so surprised and frustrated by the lack of this in Python.