[FIX] queue_job: runner - filedescriptor out of range in select

Use the most efficient Selector implementation available on the current platform

Odoo supports only SelectSelector but it is a little obsolete

python >= 3.4 supports a new high-level library Selectors:
 - https://docs.python.org/es/3/library/selectors.html

It could to auto-choose the following ones:
 - SelectSelector
 - PollSelector
 - EpollSelector
 - DevpollSelector
 - KqueueSelector

Using the DefaultSelector class the most efficient implementation available on the current platform will be use:
 - https://docs.python.org/3/library/selectors.html#selectors.DefaultSelector

It helps to support better the resources of the system

Using SelectSelector you are not able to run workers >=255

If you set `ulimit -n 10240` and run `odoo-bin --workers=255`
the following error is raised:

    Traceback (most recent call last):
    File "odoo/service/server.py", line 926, in run
        self.sleep()
    File "odoo/service/server.py", line 852, in sleep
        sel.select(self.beat)
    File "python3.8/lib/python3.8/selectors.py", line 323, in select
        r, w, _ = self._select(self._readers, self._writers, [], timeout)
    ValueError: filedescriptor out of range in select()

But using PollSelector it is not reproduced even using more workers

Most of platform supports PollSelector but using DefaultSelector we can be sure
that even too old system are supported too

And using this High-level library will allow to use the future new improvements

e.g. Epoll has better performance improvements

More info about:
 - https://devarea.com/linux-io-multiplexing-select-vs-poll-vs-epoll
 - redis/redis-py#486
 - odoo/odoo#84684

queue_job/jobrunner/runner.py

@@ -142,7 +142,7 @@
 import datetime
 import logging
 import os
-import select
+import selectors
 import threading
 import time
 from contextlib import closing, contextmanager
@@ -162,6 +162,8 @@
 
 _logger = logging.getLogger(__name__)
 
+select = selectors.DefaultSelector
+
 
 # Unfortunately, it is not possible to extend the Odoo
 # server command line arguments, so we resort to environment variables
@@ -485,10 +487,16 @@ def wait_notification(self):
         # probably a bug
         _logger.debug("select() timeout: %.2f sec", timeout)
         if timeout > 0:
-            conns, _, _ = select.select(conns, [], [], timeout)
             if conns and not self._stop:
-                for conn in conns:
-                    conn.poll()
+                with select() as sel:
+                    for conn in conns:
+                        sel.register(conn, selectors.EVENT_READ)
+                    events = sel.select(timeout=timeout)
+                    for key, _mask in events:
+                        if key.fileobj == self._stop_pipe[0]:
+                            # stop-pipe is not a conn so doesn't need poll()
+                            continue
+                        key.fileobj.poll()
 
     def stop(self):
         _logger.info("graceful stop requested")