[Disco] Propagate structlog/logging config to workers (apache#16715)

This is a follow-up to apache#16618, which propagates the `structlog`
configuration to disco worker processes.  For configurations that
use `structlog.stdlib` to integrate `structlog` with the stdlib
`logging` module, this integration must also be forwarded.

python/tvm/runtime/disco/session.py

@@ -18,6 +18,7 @@
 with the distributed runtime.
 """
 
+import logging
 import os
 import pickle
 from typing import Any, Callable, Optional, Sequence, Union
@@ -402,7 +403,19 @@ def _configure_structlog(self) -> None:
         except ImportError:
             return
 
-        config = pickle.dumps(structlog.get_config())
+        root_logger = logging.getLogger()
+        if len(root_logger.handlers) == 1 and isinstance(
+            root_logger.handlers[0].formatter, structlog.stdlib.ProcessorFormatter
+        ):
+            stdlib_formatter = root_logger.handlers[0].formatter
+        else:
+            stdlib_formatter = None
+
+        stdlib_level = root_logger.level
+
+        full_config = (structlog.get_config(), stdlib_formatter, stdlib_level)
+
+        config = pickle.dumps(full_config)
         func = self.get_global_func("runtime.disco._configure_structlog")
         func(config, os.getpid())
 
@@ -428,8 +441,18 @@ def _configure_structlog(pickled_config: bytes, parent_pid: int) -> None:
 
     import structlog  # pylint: disable=import-outside-toplevel
 
-    config = pickle.loads(pickled_config)
-    structlog.configure(**config)
+    full_config = pickle.loads(pickled_config)
+    structlog_config, stdlib_formatter, stdlib_level = full_config
+
+    root_logger = logging.getLogger()
+
+    root_logger.setLevel(stdlib_level)
+    if stdlib_formatter is not None:
+        handler = logging.StreamHandler()
+        handler.setFormatter(stdlib_formatter)
+        root_logger.addHandler(handler)
+
+    structlog.configure(**structlog_config)
 
 
 @register_func("runtime.disco._import_python_module")