Prevent Thrift errors from successfully generating schemas #150
Description
See a recent run where we had an undefined value:
- Android https://github.com/guardian/bridget/actions/runs/8633992774/job/23668359580#step:4:1691
- iOS did not even have an error… https://github.com/guardian/bridget/actions/runs/8633992774/job/23668359871
- NPM’s error is different: https://github.com/guardian/bridget/actions/runs/8633992774/job/23668359259#step:5:10
We should fail earlier if the model is incorrect!