bitbake: bb/cooker: BBCooker stops notifier at shutdown

At end of  BBCooker needs to release fd's associated with pyinotify
watchers to  avoid: Too many open files (EMFILE) error in different
scenarios like several instances of tinfoil.

[YOCTO #10873]

(Bitbake rev: ae6045b84978940c365c95c33d6996359c3e299d)

Signed-off-by: Aníbal Limón <anibal.limon@linux.intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

bitbake/lib/bb/cooker.py

@@ -1731,6 +1731,8 @@ class BBCooker:
 
         if self.parser:
             self.parser.shutdown(clean=not force, force=force)
+        self.notifier.stop()
+        self.confignotifier.stop()
 
     def finishcommand(self):
         self.state = state.initial