Don't serialize 'compatible' metadata key

It is already serialised in the 'hardware compatible' settings.

plugins/XmlMaterialProfile/XmlMaterialProfile.py

@@ -144,7 +144,7 @@ class XmlMaterialProfile(InstanceContainer):
         # setting_version is derived from the "version" tag in the schema, so don't serialize it into a file
         if ignored_metadata_keys is None:
             ignored_metadata_keys = set()
-        ignored_metadata_keys |= {"setting_version", "definition", "status", "variant", "type", "base_file", "approximate_diameter", "id", "container_type", "name"}
+        ignored_metadata_keys |= {"setting_version", "definition", "status", "variant", "type", "base_file", "approximate_diameter", "id", "container_type", "name", "compatible"}
         # remove the keys that we want to ignore in the metadata
         for key in ignored_metadata_keys:
             if key in metadata: