chore: try to resolve test flakiness

1. Disclose test_offset_converter's unresponsiveness
2. Remove test_pthread_wait64_notify's TimeoutNegativeWarning

Author: mighty1231

test/browser/test_offset_converter.c

@@ -12,10 +12,15 @@ void magic_test_function(void) {
       out(x);
       fetch('http://localhost:8888?stdout=' + encodeURIComponent(x));
     }
-    report('magic_test_function: input=' + $0);
-    var converted = wasmOffsetConverter.getName($0);
-    report('magic_test_function: converted=' + converted);
-    return converted == 'magic_test_function';
+    try {
+      report('magic_test_function: input=' + $0);
+      var converted = wasmOffsetConverter.getName($0);
+      report('magic_test_function: converted=' + converted);
+      return converted == 'magic_test_function';
+    } catch (e) {
+      report(e?.message + e?.stack);
+      return false;
+    }
   }, get_pc());
   assert(result);
 }

test/test_core.py

@@ -2604,6 +2604,9 @@ def test_pthread_wait32_notify(self):
   @node_pthreads
   @no_wasm2js('https://github.com/WebAssembly/binaryen/issues/5991')
   def test_pthread_wait64_notify(self):
+    # node version >= 23 warns on emscripten_set_timeout_loop
+    #  that sets setTimeout with negative value
+    self.node_args += ['--disable-warning=TimeoutNegativeWarning']
     self.do_run_in_out_file_test('atomic/test_wait64_notify.c')
 
   @node_pthreads