Jenkins builds timeout while waiting for executor

[kocolosk]

Description

We have a 15 minute timeout set for the "Build Release Tarball" phase. Occasionally time spent waiting for an executor seems to be counted against this budget, e.g.

https://builds.apache.org/blue/organizations/jenkins/CouchDB/detail/jenkins-cpse-debugging/14/pipeline/

I don't think that's the intention. I don't have time (hah!) to dig into it right now but wanted to file for posterity.

Expected Behaviour

The timeout should only start once an executor is allocated to that stage of the pipeline.

[kocolosk]

Rediscovered this and fixed it in #3913