CI: Adjust how we specify what to exclude from failure artifacts (#3091)
CI: Adjust how we specify what to exclude from failure artifacts (#3091)

We weren't using a recognized notation, and so our artifacts were
including huge files unintentionally.
OpenImageIO/oiio,OpenImageIO/oiio,lgritz/oiio,OpenImageIO/oiio,OpenImageIO/oiio,lgritz/oiio,lgritz/oiio,lgritz/oiio