Don't launch ImageOptim for unsupported files

[mat-u]

When I export an asset to PDF, ImageOptim is executed. But it doesn't support compression for PDF, Webp, EPS, etc.

Is there a way to exclude these files when exporting?

[dnlswan]

I'd also be happy to see this! I've been making a lot of PDFs lately so this just often comes up as an undesired interruption while working.