`helm_plugin and helm_plugin_info remove unused parameter release_namespace` (#85)

* remove unused parameter release_namespace from documentation

* Update changelogs/fragments/85_helm_plugin.yaml

Co-authored-by: Mike Graves <mgraves@redhat.com>

plugins/modules/helm_plugin_info.py

@@ -20,13 +20,6 @@ requirements:
 description:
   -  Gather information about Helm plugins installed in namespace.
 options:
-  # TODO: (akasurde) Remove this in version 2.0
-  release_namespace:
-    description:
-      - Kubernetes namespace where the helm plugins are installed.
-    type: str
-    aliases: [ namespace ]
-
 #Helm options
   plugin_name:
     description:
@@ -88,7 +81,6 @@ def main():
     module = AnsibleModule(
         argument_spec=dict(
             binary_path=dict(type='path'),
-            release_namespace=dict(type='str', aliases=['namespace']),
             plugin_name=dict(type='str',),
             # Helm options
             context=dict(type='str', aliases=['kube_context'], fallback=(env_fallback, ['K8S_AUTH_CONTEXT'])),