I can reproduce this when enabling verbose logging (X-Wikimedia-Debug) on wikidata.org
DEBUG resourceloader mwdebug1002 wikidatawiki Unexpected general module "ext.math.scripts" in styles queue.
It seems this module doesn't seem to need any kind of migration. It contains only a javascript file and it being queued via addModuleStyles() is entirely a no-op.
"ext.math.scripts": { "scripts": "ext.math.js" },