Merge branch 'remove-network-policy-editor-ff' into 'master'

Remove network_policy_editor flag definition

See merge request gitlab-org/gitlab!43793

ee/config/feature_flags/development/network_policy_editor.yml

----
-name: network_policy_editor
-introduced_by_url: 
-rollout_issue_url: 
-group: 
-type: development
-default_enabled: false