Merge #14069: qa: Use assert not BOOST_CHECK_* from multithreaded tests

737670c036 Use assert when running from multithreaded code as BOOST_CHECK_* are not thread safe (Jesse Cohen)

Pull request description:

  Resolves thread sanitizer failure @MarcoFalke found in #14058

Tree-SHA512: 24d86c2cdae21fee029ee4b06f633de4b3e655d3371d97f09db6fd3f24b29388a78110996712249c49e7fefa7bbc3d3c405d8b480382174831fe2f9a042a557e

src/test/scheduler_tests.cpp

@@ -138,11 +138,11 @@ BOOST_AUTO_TEST_CASE(singlethreadedscheduler_ordered)
     // the callbacks should run in exactly the order in which they were enqueued
     for (int i = 0; i < 100; ++i) {
         queue1.AddToProcessQueue([i, &counter1]() {
-            BOOST_CHECK_EQUAL(i, counter1++);
+            assert(i == counter1++);
         });
 
         queue2.AddToProcessQueue([i, &counter2]() {
-            BOOST_CHECK_EQUAL(i, counter2++);
+            assert(i == counter2++);
         });
     }