CI: add missing apt update

[jpnurmi]

Build jobs have started failing with errors like:

Fetched 11.0 MB in 7s (1537 kB/s)
E: Failed to fetch http://azure.archive.ubuntu.com/ubuntu/pool/main/m/mesa/libegl-mesa0_22.0.5-0ubuntu0.1_amd64.deb  404  Not Found [IP: 40.119.46.219 80]
E: Failed to fetch http://azure.archive.ubuntu.com/ubuntu/pool/main/m/mesa/libegl1-mesa-dev_22.0.5-0ubuntu0.1_amd64.deb  404  Not Found [IP: 40.119.46.219 80]
E: Unable to fetch some archives, maybe run apt-get update or try with --fix-missing?
Error: Process completed with exit code 100.

• https://github.com/ubuntu/yaru_widgets.dart/actions/runs/3891996009/jobs/6643045813
• https://github.com/ubuntu/yaru_widgets.dart/actions/runs/3891936309/jobs/6643042784
• https://github.com/ubuntu/yaru_widgets.dart/actions/runs/3892061928/jobs/6643034087
• ...

[Jupi007]

Thanks, it was indeed a problem of outdated apt packages informations 👍
I also sometime have this problem when I start a VM since a long time, and I try to update it. Run apt update is always the solution in that case.

[jpnurmi]

Thanks! Now to rebase all PRs 😅