Invalid requests to Typekit API

We're requesting from the Typekit API variations that don't exist for particular fonts. I receive emails for API request failures, and I've noticed a lot of these errors:

`{"errors":["The variations 'i3', 'i9' are not allowed for font family 'sskw'"]}`
`{"errors":["The variations 'i3', 'i8' are not allowed for font family 'nqdy'"]}`

I haven't reviewed _every_ error report, but skimming them indicates the problem is limited to those two fonts and those particular variations.

Start by tracing where this plugin builds Typekit API requests and how font variations are selected for families sskw and nqdy. Confirm the available variations for those fonts, then verify that generated requests no longer include i3, i8, or i9 and that the reported API errors are resolved.

Written by the indexing model from the issue text.