[Dev] Jenkins: transition to new x86-64 build machine

[nurupo]

Hello,

Since the build machines on our build server (https://build.tox.chat) 
are underutilized, we are transitioning from using a build machine that 
is always online to a build machine that would be created automatically 
on demand. This is supposed to reduce how much we pay for build 
machines. It also has other benefits, such as a fully documented setup 
of the build machine and the fact that the on-demand build machine is 
always recreated off a base image, without retaining any build state.

Currently we are transitioning only the x86-64 build machine. The 
on-demand build machine was set up from scratch, so it might be missing 
packages or configuration files that are present on the 24/7 online 
build machine. Because of this, we have set up a test on-demand build 
machine that you can run your build jobs on, to give you a chance to see 
and report any issues with the on-demand build machine before we 
transition. We plan for the transition to take place in 14 days, on July 
10th, unless we find any issues during the testing. To run your build 
job on the test on-demand build machine, restrict it to run on a node 
labeled "test-linux-x86-64.slave.tox.chat". If the on-demand build 
machine is not online when you trigger the build job, it should come 
online in about 5 to 12 minutes. Email me any issues you find during 
your test of the on-demand build machine.

-- 
Regards,
nurupo