Respect PREFECT__CLOUD__SEND_FLOW_RUN_LOGS

[EmilRex]

The PREFECT__CLOUD__SEND_FLOW_RUN_LOGS environment variables is ignored when explicitly set. This change avoids overwriting it with a default value when set.

Closes #5521

[zanieb]

Hm. Looking back at #4487 I do not think this setting is intended to be used this way. The engineer running the agent determines if flow run logs can be sent to Cloud. If I configure my agent not to send logs to Cloud, I would be pretty upset if any user could send logs by adding an environment variable.

Perhaps we should allow this to be turned off per flow run but never turned on unless already allowed at the agent level. We'll want to check that this meets Recursion's requirements.

As is, I think this could be seen as a security risk.

[EmilRex]

I would be pretty upset if any user could send logs by adding an environment variable.

Good point, I hadn't considered that.

Perhaps we should allow this to be turned off per flow run but never turned on unless already allowed at the agent level.

We'll want to check that this meets Recursion's requirements.
Agreed.

[johnurbanik]

Yes, I think that agent having flow logs off should take precedence, but if the agent has flow logs on, it should be possible to turn it off at the flow run level.

Updating the docs to communicate that clearly once implemented would also be great.

[zanieb]

Yes, I think that agent having flow logs off should take precedence, but if the agent has flow logs on, it should be possible to turn it off at the flow run level.

Great! Definitely down for that implementation. @EmilRex you'll also need to implement this for all of the other agent types.

[zanieb]

Can you write tests covering our new expected behavior as well?