Mark several old feature flags as required

[Why]
User have to upgrade to RabbitMQ 4.2.x first before jumping to 4.3.x+.

In particular, `rabbit_exchange_type_local_random` and
`detailed_queues_endpoint` were introduced a long time ago.

Author: dumbbell

deps/rabbit/src/rabbit_core_ff.erl

@@ -207,14 +207,14 @@
 -rabbit_feature_flag(
    {'rabbitmq_4.1.0',
     #{desc          => "Allows rolling upgrades to 4.1.x",
-      stability     => stable,
+      stability     => required,
       depends_on    => ['rabbitmq_4.0.0']
      }}).
 
 -rabbit_feature_flag(
    {'rabbitmq_4.2.0',
     #{desc          => "Allows rolling upgrades to 4.2.x",
-      stability     => stable,
+      stability     => ,
       depends_on    => ['rabbitmq_4.1.0'],
       callbacks     => #{enable => {rabbit_khepri, enable_feature_flag}}
      }}).

deps/rabbit/src/rabbit_exchange_type_local_random.erl

@@ -11,7 +11,7 @@
 
 -rabbit_feature_flag({?MODULE,
                       #{desc => "Local random exchange",
-                        stability => stable
+                        stability => required
                        }}).
 
 -rabbit_boot_step({?MODULE,

deps/rabbitmq_management/src/rabbit_mgmt_app.erl

@@ -29,7 +29,7 @@
 -rabbit_feature_flag(
    {detailed_queues_endpoint,
     #{desc          => "Add a detailed queues HTTP API endpoint. Reduce number of metrics in the default endpoint.",
-      stability     => stable,
+      stability     => required,
       depends_on    => [feature_flags_v2]
      }}).