ESCET builds on Jenkins for `develop` get aborted

Builds 289, 290 and 291 all got aborted.

Mail title: Build Aborted Eclipse ESCET build » develop #289!

Mail body: Check console output at https://ci.eclipse.org/escet/job/ESCET%20build/job/develop/289/ to view the results.

Build output:

[2024-06-10T14:27:37.331Z] + git commit -q -m 'Website release nightly.' -m 'Generated from commit 4146d1ce9e78939822c13aee347850da6ad379ca.'
[2024-06-10T14:27:37.331Z] + git push
Cancelling nested steps due to timeout
[2024-06-10T14:27:40.191Z] Sending interrupt signal to process
[2024-06-10T14:27:40.626Z] Killed by signal 15.
[2024-06-10T14:27:40.626Z] send-pack: unexpected disconnect while reading sideband packet
[2024-06-10T14:27:40.888Z] fatal: the remote end hung up unexpectedly
[2024-06-10T14:27:40.900Z] script returned exit code 128
[Pipeline] }
[2024-06-10T14:27:45.496Z] $ ssh-agent -k
[2024-06-10T14:27:45.506Z] unset SSH_AUTH_SOCK;
[2024-06-10T14:27:45.507Z] unset SSH_AGENT_PID;
[2024-06-10T14:27:45.507Z] echo Agent pid 13240 killed;
[2024-06-10T14:27:45.512Z] [ssh-agent] Stopped.

It gets cancelled at 14:27:37, and it started just before 13:27:41, so an hour has past. I think the 1 hour timeout is hit. We used to not get close to it. Maybe because we deploy nightlies, it now takes longer. Maybe we just have more code to compile, more documentation to generate, more tests to run, etc. Maybe the cluster on which it runs is doing more in parallel and is just slower. I don't know for sure.

I think we should increase the timeout to solve the immediate issue.