Add faketime support for builds and autopkgtests
This MR adds faketime support for build and autopkgtest jobs on amd64 and i386.
The goal is to detect Y2038 and other time-related issues early in CI.
The jobs use libfaketime to simulate the system clock at the Y2038 boundary.
They run with LD_PRELOAD and FAKETIME set during builds and autopkgtests.
By default, these jobs are disabled.
The default simulated date is fixed to 2038-01-19 03:14:08.
Closes: #411
Edited by Aquila Macedo