I interviewed for(and got offered but didn't accept because the compensation wasn't worth moving from my cushy C#/typescript job) a PHP role a couple weeks ago, which I didn't think anyone used any more and they certainly don't teach in 99% of uni courses, I only had experience with it from personal project before even uni, terrible language btw don't recommend

italian

Any functional or logical language: Clojure, Scheme, Lisp, Haskell, Prolog, ...

To a lesser degree C and C++, plenty of old talent but not a lot of young one.

Functional languages like Scala, Haskell, and Lisp dialects are prominent in some industries. Scala is especially workable since it runs on the JVM so there are plenty of Java shops with a chunk of Scala that needs maintaining. Haskell is a little worse on pay since it's a very enthusiast-driven language, so people will take a hit on pay to write the language they like. Most of the jobs are also in crypto and other evil shit, so it's kind of depressing when the market is otherwise cold.

Rust is still in this category, though it's in a hype cycle right now so the market can be weird. Modern PHP is having something of a renaissance, so if you don't still write the ancient garbage version then you can get into some neat spaces.

I also imagine knowing how to write modern C++ will probably get you quite far, considering how much of the industry still writes the C++ I learned in high school.