Do not warn about subscriptions being used in non-reactive contexts (#17240)

Force re-frame to stop warning about subscriptions in non-reactive contexts
while executing subscription tests (i.e. unit tests using the macro
test-helpers.unit/deftest-sub).

The net result? No more hundreds of useless warnings in the output of make test.

    re-frame: Subscribe was called outside of a reactive context.
     See: https://day8.github.io/re-frame/FAQs/UseASubscriptionInAJsEvent/

The warning is actually useful in production code, but in a subscription test we
already know we're never inside a reactive context.

src/test_helpers/unit.clj

@@ -51,10 +51,12 @@
        (let [~args [sub-name#]]
          (restore-app-db
           (fn []
-            ~@(clojure.walk/postwalk-replace
-               {'cljs.test/testing `testing-subscription
-                'testing           `testing-subscription}
-               body)))))))
+            ;; Do not warn about subscriptions being used in non-reactive contexts.
+            (with-redefs [re-frame.interop/debug-enabled? false]
+              ~@(clojure.walk/postwalk-replace
+                 {'cljs.test/testing `testing-subscription
+                  'testing           `testing-subscription}
+                 body))))))))
 
 (defmacro use-log-fixture
   "Register log fixture which allows inspecting all calls to `taoensso.timbre/log`.