python3Packages.rq: disable racy test

It reaps a worker and checks if it has been removed right after, but this
is apparently racy.

(cherry picked from commit 56913ae775)

pkgs/development/python-modules/rq/default.nix

@@ -76,6 +76,10 @@ buildPythonPackage (finalAttrs: {
       # PermissionError: [Errno 13] Permission denied: '/tmp/rq-tests.txt'
       "test_deleted_jobs_arent_executed"
       "test_suspend_worker_execution"
+    ]
+    ++ lib.optionals stdenv.hostPlatform.isLinux [
+      # no delay between reaping worker and checking; racy
+      "test_reap_workers"
     ];
 
   pythonImportsCheck = [ "rq" ];