add sources.list for jammy

files/etc/apt/sources.list.jammy

+deb http://debian.stanford.edu/ubuntu jammy          main multiverse restricted universe
+deb http://debian.stanford.edu/ubuntu jammy-security main multiverse restricted universe
+deb http://debian.stanford.edu/ubuntu jammy-updates  main multiverse restricted universe
+
+# jammy is based on Debian unstable after the bullseye release but prior
+# to the bookworm release. Thus we point to the bookworm repositories for
+# Debian packages, e.g., for things like stanford-keyring.
+# See also https://wiki.ubuntu.com/DebianImportFreeze
+
+# The Stanford-specific Debian archive and source tree (world-accessible).
+deb     http://debian.stanford.edu/debian-stanford bookworm main non-free contrib
+deb-src http://debian.stanford.edu/debian-stanford bookworm main non-free contrib
+
+# The Stanford restricted Debian archive and source tree.
+deb     http://debian.stanford.edu/debian-local bookworm main non-free contrib
+deb-src http://debian.stanford.edu/debian-local bookworm main non-free contrib
+
+# Additional Stanford-local backports.
+deb     http://debian.stanford.edu/debian-stanford bookworm-backports main non-free contrib
+deb-src http://debian.stanford.edu/debian-stanford bookworm-backports main non-free contrib