Deprecate support for networking-mlnx again

The networking-mlnx project[1] looks unmaintained again. The project
does not provide releases since 2023.1.

[1] https://opendev.org/x/networking-mlnx

Change-Id: Ifba4c6d2061aab72294d4cee46fadfae0bf30dc8

manifests/agents/ml2/mlnx.pp

@@ -1,6 +1,7 @@
 #
 # == Class: neutron::agents::ml2::mlnx
 #
+# DEPRECATED !
 # Setups MLNX neutron agent when using ML2 plugin
 #
 # === Parameters
@@ -63,6 +64,7 @@ class neutron::agents::ml2::mlnx (
   $ipoib_physical_interface                        = $facts['os_service_default'],
   $enable_multi_interface_driver_cache_maintenance = false,
 ) {
+  warning('Support for networking-mlnx has been deprecated')
 
   include neutron::deps
   include neutron::params

manifests/plugins/ml2/mellanox.pp

@@ -1,4 +1,7 @@
 #
+# == Class: neutron::plugins::ml2::mellanox
+#
+# DEPRECATED !
 # Install the Mellanox plugins and generate the config file
 # from parameters in the other classes.
 #
@@ -14,6 +17,7 @@
 class neutron::plugins::ml2::mellanox (
   $package_ensure = 'present'
 ) {
+  warning('Support for networking-mlnx has been deprecated')
 
   include neutron::deps
   include neutron::params

manifests/plugins/ml2/mellanox/mlnx_sdn_assist.pp

@@ -1,4 +1,7 @@
 #
+# == Class: neutron::plugins::ml2::mellanox::mlnx_sdn_assist
+#
+# DEPRECATED !
 # Install the OpenDaylight and generate config file
 # from parameters in the other classes.
 #
@@ -44,6 +47,7 @@ class neutron::plugins::ml2::mellanox::mlnx_sdn_assist (
   $bind_normal_ports          = false,
   $bind_normal_ports_physnets = [],
 ) {
+  warning('Support for networking-mlnx has been deprecated')
 
   include neutron::deps
   require neutron::plugins::ml2

releasenotes/notes/deprecate-networking-mlnx-1585b2f692e2cfe5.yaml

@@ -0,0 +1,5 @@
+---
+deprecations:
+  - |
+    Support for networking-mlnx has been deprecated and will be removed in
+    a future release.