➕ Add ubuntu CI

ci/ubuntu-install-packages

@@ -0,0 +1,14 @@
+#!/bin/sh
+
+# This script gets run in weird environments that have been stripped of just
+# about every inessential thing. In order to keep this script versatile, we
+# just install 'sudo' and use it like normal if it doesn't exist. If it doesn't
+# exist, we assume we're root. (Otherwise we ain't doing much of anything
+# anyway.)
+if ! command -V sudo; then
+  apt-get update
+  apt-get install -y --no-install-recommends sudo
+fi
+sudo apt-get update
+sudo apt-get install -y --no-install-recommends \
+  zsh xz-utils liblz4-tool musl-tools brotli zstd