fuzz: Abort when global PRNG is used before SeedRand::ZEROS

src/test/util/setup_common.cpp

@@ -79,7 +79,9 @@ constexpr inline auto TEST_DIR_PATH_ELEMENT{"test_common bitcoin"}; // Includes
 static FastRandomContext g_rng_temp_path;
 static const bool g_rng_temp_path_init{[] {
     // Must be initialized before any SeedRandomForTest
+    Assert(!g_used_g_prng);
     (void)g_rng_temp_path.rand64();
+    g_used_g_prng = false;
     return true;
 }()};