Prevent loading of namespaces that are skipped

Via @borkdude on Clojurians Slack

When using kaocha, is there an equivalent to -n from the cognitect test runner or :only from leiningen, from the command line?
nm, got it: https://cljdoc.org/d/lambdaisland/kaocha/1.0.632/doc/6-focusing-and-skipping#on-a-namespace
I'm trying to port this:

clojure -A:test -n babashka.pods.jvm-test
;;=>
clojure -A:test:kaocha --focus babashka.pods.jvm-testclojure -A:sci:test -n babashka.pods.sci-test
;;=>
clojure -A:sci:test:kaocha --focus babashka.pods.sci-test

This one:

clojure -A:test:kaocha --focus babashka.pods.jvm-test

doesn't work, since the sci library is (deliberately!) not available on the classpath. The code should run without the library, which is part of my test.
With the Cognitest test runner or leiningen that works, but with kaocha it doesn't:

$ clojure -A:test:kaocha --focus babashka.pods.jvm-test
WARNING: :focus [:babashka.pods.jvm-test] did not match any tests.
[E]
Randomized with --seed 2027872620ERROR in unit (babashka/pods/sci.clj:1)
Exception: clojure.lang.Compiler$CompilerException: Syntax error compiling at (babashka/pods/sci.clj:1:1).
#:clojure.error{:phase :compile-syntax-check, :line 1, :column 1, :source "babashka/pods/sci.clj"}

So my proposal would be that focus should not load files other than it needs.

Start by tracing Kaocha's command-line --focus handling and the test namespace discovery/loading path; the issue provides the babashka.pods.jvm-test command as a reproduction. Run that focused command with the optional sci namespace unavailable, and consider the work done when skipped namespaces are not loaded and the focused test runs successfully.