test(browser): name each thread in the slow-reset stacks

Before Python 3.14 faulthandler prints thread ids only, so the report
now lists which name each id belongs to. CI on 3.10 to 3.13 failed the
unit test that looks for the blocked thread by name.

tests/browser/slow_reset_watch.py

@@ -114,10 +114,16 @@ def thread_stacks() -> list[str]:
     Formatting sys._current_frames() showed a thread blocked in SQLite as idle
     (Python 3.14); faulthandler reports where each thread really is.
     """
+    # Before Python 3.14 faulthandler prints ids only; name each id here.
+    names = [
+        f"thread 0x{thread.ident:016x} is {thread.name}"
+        for thread in threading.enumerate()
+        if thread.ident is not None
+    ]
     with tempfile.TemporaryFile() as dump:
         faulthandler.dump_traceback(file=dump, all_threads=True)
         dump.seek(0)
-        return dump.read().decode("utf-8", "replace").splitlines()
+        return [*names, *dump.read().decode("utf-8", "replace").splitlines()]
 
 
 def executor_state(loop: asyncio.AbstractEventLoop) -> list[str]:

tests/test_browser_slow_reset_watch.py

@@ -71,7 +71,7 @@ class TestResetWatch(unittest.TestCase):
         text = "\n".join(report)
         self.assertIn("POST /__test__/reset still running after", text)
         self.assertIn("database: 1 connections", text)
-        self.assertIn("[held-up]", text)
+        self.assertIn(f"thread 0x{worker.ident:016x} is held-up", text)
         self.assertIn("in blocked_here", text)
 
         watch.record_call("seed", 0.25, 1.5)