Ruby [1], JavaScript (when running in NodeJS) and PHP are single-threaded. Perl is single threaded as well but it features something like to what is being proposed in PEP 554 (https://peps.python.org/pep-0554/).
I know Clojure is often described as a dynamic language and that it has some concurrency primitives, but my knowledge ends here.
[1] Just like Python, Ruby does have implementations that allow multi-threading.
Ruby is not single threaded even in its default implementation, but it does have a global value lock that is equivalent to the GIL. Not only does it have threads, it also has fibers which allow for more cooperative scheduling.
I know Clojure is often described as a dynamic language and that it has some concurrency primitives, but my knowledge ends here.
[1] Just like Python, Ruby does have implementations that allow multi-threading.