GA CI failures due to stale apt data

We first saw this on aarchxx with the qemu package and I put in an "apt update" in PR #4763. I did not put that in every job since it takes a solid 30s and would thus be a 5%+ time increase for every job. But we're now seeing failures in other places:

Package build failed which is not good: https://github.com/DynamoRIO/dynamorio/runs/2100301478?check_suite_focus=true

E: Failed to fetch http://ppa.launchpad.net/ubuntu-toolchain-r/test/ubuntu/pool/main/g/gcc-9/libx32gcc1_9.3.0-10ubuntu2~16.04_amd64.deb  404  Not Found [IP: 91.189.95.85 80]
E: Failed to fetch http://ppa.launchpad.net/ubuntu-toolchain-r/test/ubuntu/pool/main/g/gcc-9/lib32gomp1_9.3.0-10ubuntu2~16.04_amd64.deb  404  Not Found [IP: 91.189.95.85 80]
E: Failed to fetch http://ppa.launchpad.net/ubuntu-toolchain-r/test/ubuntu/pool/main/g/gcc-9/libx32gomp1_9.3.0-10ubuntu2~16.04_amd64.deb  404  Not Found [IP: 91.189.95.85 80]
E: Failed to fetch http://ppa.launchpad.net/ubuntu-toolchain-r/test/ubuntu/pool/main/g/gcc-9/lib32itm1_9.3.0-10ubuntu2~16.04_amd64.deb  404  Not Found [IP: 91.189.95.85 80]
E: Failed to fetch http://ppa.launchpad.net/ubuntu-toolchain-r/test/ubuntu/pool/main/g/gcc-9/libx32itm1_9.3.0-10ubuntu2~16.04_amd64.deb  404  Not Found [IP: 91.189.95.85 80]
E: Failed to fetch http://ppa.launchpad.net/ubuntu-toolchain-r/test/ubuntu/pool/main/g/gcc-9/lib32atomic1_9.3.0-10ubuntu2~16.04_amd64.deb  404  Not Found [IP: 91.189.95.85 80]
E: Failed to fetch http://ppa.launchpad.net/ubuntu-toolchain-r/test/ubuntu/pool/main/g/gcc-9/libx32atomic1_9.3.0-10ubuntu2~16.04_amd64.deb  404  Not Found [IP: 91.189.95.85 80]
E: Failed to fetch http://ppa.launchpad.net/ubuntu-toolchain-r/test/ubuntu/pool/main/g/gcc-9/libx32stdc++6_9.3.0-10ubuntu2~16.04_amd64.deb  404  Not Found [IP: 91.189.95.85 80]
E: Failed to fetch http://ppa.launchpad.net/ubuntu-toolchain-r/test/ubuntu/pool/main/g/gcc-9/lib32quadmath0_9.3.0-10ubuntu2~16.04_amd64.deb  404  Not Found [IP: 91.189.95.85 80]
E: Failed to fetch http://ppa.launchpad.net/ubuntu-toolchain-r/test/ubuntu/pool/main/g/gcc-9/libx32quadmath0_9.3.0-10ubuntu2~16.04_amd64.deb  404  Not Found [IP: 91.189.95.85 80]

A bunch of tests are now failing with similar errors.