Add ubuntu:20.04 toolchains and tag debian-11 toolchains with allow_failure
Summary
Add toolchains for ubuntu:20.04, gcc-9-20 and gcc-10-20, and add the tag allow_failure=true
for all debian-11 toolchains.
Details
debian-11 images seem to have a lot of problems recently. Since it is a work-in-progress distribution, not yet stable, I switch to a released linux distribution for the same toolchains to make the ci system a bit more stable. Once debian-11 is released as stable, it can be switched back.
Note
- This MR needs an update of the ubuntu-20.04 image in the docker/ci repository, see docker/ci!76 (merged)
- The change contains a sorting of the jobs by base image and compiler version
Edited by Simon Praetorius