Bump min openstacksdk version for os_network/{port_security_enabled,mtu}

To make use of the port_security_enabled [a] and mtu [b] parameters,
[c] and [d] need to be present in the openstacksdk or the os_network
module with return an error like:

TypeError: create_network() got an unexpected keyword argument 'port_security_enabled'

or:

TypeError: create_network() got an unexpected keyword argument 'mtu'

To handle this, we fail the module if one of the arguments are used
and the minimum openstacksdk version for that argument is not met.

[a] eaf238b033
[b] c6a8e99d34
[c] 8eb788af07
[d] a1fc820a2f

Backport-of: https://review.opendev.org/708119
Fixes: https://github.com/ansible/ansible/issues/62062
Change-Id: I2b80dc721a08bbdb530af3705ae99cf1b579d9f0

changelogs/fragments/62062-os_network-openstacksdk-min.yml

@@ -0,0 +1,3 @@
+bugfixes:
+  - Bump the minimum openstacksdk version to 0.18.0 when os_network
+    uses the port_security_enabled or mtu arguments.

changelogs/fragments/64495-os_network-openstacksdk-min.yml

@@ -1,3 +1,3 @@
 bugfixes:
-  - bump the minimum openstacksdk version when os_network
+  - Bump the minimum openstacksdk version to 0.29.0 when os_network
     uses the dns_domain argument

lib/ansible/modules/cloud/openstack/os_network.py

@@ -73,14 +73,14 @@ options:
      description:
         -  Whether port security is enabled on the network or not.
            Network will use OpenStack defaults if this option is
-           not utilised.
+           not utilised. Requires openstacksdk>=0.18.
      type: bool
      version_added: "2.8"
    mtu:
      description:
        -  The maximum transmission unit (MTU) value to address fragmentation.
           Network will use OpenStack defaults if this option is
-          not provided.
+          not provided. Requires openstacksdk>=0.18.
      type: int
      version_added: "2.9"
    dns_domain:
@@ -199,16 +199,22 @@ def main():
     provider_segmentation_id = module.params['provider_segmentation_id']
     project = module.params['project']
 
-    net_create_kwargs = {
-        'port_security_enabled': module.params['port_security_enabled'],
-        'mtu_size': module.params['mtu']
-    }
+    net_create_kwargs = {}
+    min_version = None
+
+    if module.params['mtu'] is not None:
+        min_version = '0.18.0'
+        net_create_kwargs['mtu_size'] = module.params['mtu']
+
+    if module.params['port_security_enabled'] is not None:
+        min_version = '0.18.0'
+        net_create_kwargs['port_security_enabled'] = module.params['port_security_enabled']
 
     if module.params['dns_domain'] is not None:
-        sdk, cloud = openstack_cloud_from_module(module, min_version='0.29.0')
+        min_version = '0.29.0'
         net_create_kwargs['dns_domain'] = module.params['dns_domain']
-    else:
-        sdk, cloud = openstack_cloud_from_module(module)
+
+    sdk, cloud = openstack_cloud_from_module(module, min_version)
     try:
         if project is not None:
             proj = cloud.get_project(project)