Exclude on_opened and on_closed from watcher events

We're not interested in these. `on_opened` in particular was introduced
in gorakhargosh/watchdog#941 and then partially
reverted in
gorakhargosh/watchdog@25a2d1f,
but that doesn't work for us.

Should fix #16840

lib/galaxy/util/watcher.py

@@ -130,7 +130,17 @@ class EventHandler(FileSystemEventHandler):
     def __init__(self, watcher):
         self.watcher = watcher
 
-    def on_any_event(self, event):
+    # this effectively excludes on_opened and on_closed
+    def on_moved(self, event):
+        self._handle(event)
+
+    def on_created(self, event):
+        self._handle(event)
+
+    def on_deleted(self, event):
+        self._handle(event)
+
+    def on_modified(self, event):
         self._handle(event)
 
     def _extension_check(self, key, path):