It seems plausible to maybe strip (or modify) clojure/core/server.clj and clojure/main.clj from the jar if you have a dedicated entrypoint (e.g. your own main).
As has already been stated, there’s nothing stopping someone from copying them back into the jar and bypassing your stuff though, especially if you are distributing anything in source form. If you are AOT’ing and stripping source, it’s viable. Even then, they can still probably decompile your entry point, stick some stuff in to load their own script (e.g. require clojure.repl and start the socket repl). There are layers.