🛑 HeCo Invest remote engine is down

In [`ec2aaa0`](https://github.com/integratedmodelling/upptime/commit/ec2aaa05739a53c19d60d77ee2e3bbd9a6ab2c48
), HeCo Invest remote engine (https://hecoinvest.integratedmodelling.org/modeler/) was **down**:
- HTTP code: 503
- Response time: 451 ms
