The title is inaccurate according to https://pytorch.org/hub/snakers4_silero-models_tts and the YML file in the repo.

Supported Languages and Formats As of this page update, the speakers of the following languages are supported both in 8 kHz and 16 kHz:

Russian (6 speakers) English (1 speaker) German (1 speaker) Spanish (1 speaker) French (1 speaker)

I don't see how we get 173 voices and 20 languages from that.