fix: Fixes flaky ScalablePushBandwidthThrottleIntegrationTest caused by timeout

[AlanConfluent]

Description

Because ScalablePushBandwidthThrottleIntegrationTest creates a server per test, the startup time is attributed to the test, so although there's a 2 minute limit, most of it can be taken up by this startup. When the test then runs, the server gets terminated part way through and you get a funny connection closed error rather than a timeout, leading to confusion.

This ups the timeout of this test to prevent this.

Testing done

Ran the test and simulated slow startup and was able to reproduce flaky stacktraces.

Reviewer checklist

• Ensure docs are updated if necessary. (eg. if a user visible feature is being added or changed).
• Ensure relevant issues are linked (description should include text like "Fixes #")

[agavra]

that's a super long time to start, is there any way we can make it faster?

[nateab]

LGTM!

[AlanConfluent]

that's a super long time to start, is there any way we can make it faster?

@agavra I agree. This is not ideal, but the test itself takes maybe 30 seconds at times to run which means that if the startup takes way too long, it can hit 2 minutes in really slow CI runs. I think the ideal solution would include speeding up the server startup time. That would be a good followup.