🐛(backend) adjust throttle rate from hours to minutes for request_entry

Correct throttling configuration for request_entry endpoint from hours to
minutes. Previous setting of 150 requests per hour was insufficient as
participants query approximately once per second while in the lobby.

src/backend/meet/settings.py

@@ -267,7 +267,7 @@ class Base(Configuration):
         "DEFAULT_SCHEMA_CLASS": "drf_spectacular.openapi.AutoSchema",
         "DEFAULT_THROTTLE_RATES": {
             "request_entry": values.Value(
-                default="150/hour",
+                default="150/minute",
                 environ_name="REQUEST_ENTRY_THROTTLE_RATES",
                 environ_prefix=None,
             ),