🐛 [BUG] - Synthetic Probes show a high number a 504 errors

### SLO Generator Version

v2.5.2

### Python Version

3.9

### What happened?

After designing synthetic probes and availability/latency SLOs in the CI environment, a lot of 504 errors started to show up in the logs, in a seemingly random pattern. As a result, the error budget is burning quite fast during the outages. The incident usually resolves itself in under 10 minutes, then shows up again later on.

### What did you expect?

No 504 errors and no timeouts when calling the SLO Generator.

### Screenshots

_No response_

### Relevant log output

_No response_

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