ci(ubuntu): use AWS regional mirror for apt in compile workflow

The compile_ubuntu workflow's apt operations talk directly to
archive.ubuntu.com, which round-robins across community mirrors that
occasionally serve out-of-sync index files mid-sync and break apt update
for everyone until the upstream catches up.

Apply the same mirror swap as build_deb_package.yml: rewrite the
container's apt sources to point at us-west-2.ec2.archive.ubuntu.com
before any apt operation runs, so both the inline 'apt update' and the
later Tools/setup/ubuntu.sh call benefit from the regional mirror.

Signed-off-by: Ramon Roche <mrpollo@gmail.com>

.github/workflows/compile_ubuntu.yml

@@ -38,6 +38,17 @@ jobs:
 
       - name: Fix git in container
         run: |
+          # Switch to AWS regional mirrors. runs-on instances are in us-west-2,
+          # and the EC2 archive mirrors are Canonical-operated, region-local,
+          # and sync aggressively. The default archive.ubuntu.com round-robin
+          # sometimes serves out-of-sync index files mid-sync, breaking
+          # apt-get update.
+          if [ -f /etc/apt/sources.list.d/ubuntu.sources ]; then
+            sed -i 's|http://archive.ubuntu.com/ubuntu|http://us-west-2.ec2.archive.ubuntu.com/ubuntu|g; s|http://security.ubuntu.com/ubuntu|http://us-west-2.ec2.archive.ubuntu.com/ubuntu|g' /etc/apt/sources.list.d/ubuntu.sources
+          fi
+          if [ -f /etc/apt/sources.list ]; then
+            sed -i 's|http://archive.ubuntu.com/ubuntu|http://us-west-2.ec2.archive.ubuntu.com/ubuntu|g; s|http://security.ubuntu.com/ubuntu|http://us-west-2.ec2.archive.ubuntu.com/ubuntu|g' /etc/apt/sources.list
+          fi
           # we only need this because we are running the job in a container
           # when checkout pulls git it does it in a shared volume
           # and file ownership changes between steps