fix: Fix running browser tests by gonfunko · Pull Request #9587 · RaspberryPiFoundation/blockly

The basics

The details

Resolves

This PR fixes npm run test:browser, which had been failing with Error: No test files found: "test". I'm not entirely clear why, but it seems like Mocha was not running from the path we were cding to, I assume due to either a version change or the monorepo work. In any case, the browser tests now work correctly.