[cashtab-faucet] Patch CI for correct project root

Summary: Missed this when cashtab-faucet was split out of token-server

Test Plan: proofread, CI

Reviewers: #bitcoin_abc, PiRK

Reviewed By: #bitcoin_abc, PiRK

Subscribers: PiRK

Differential Revision: https://reviews.bitcoinabc.org/D18458