Script to upgrade from focal to noble

The script is split into various stages where progress is tracked
on-disk. The script is able to resume where it was at any point, and
needs to, given multiple reboots in the middle.

The new noble-upgrade.json file shipped in the securedrop-config package
is used to control the upgrade process.

Further details of the script are explained inline and at
<https://github.com/freedomofpress/securedrop/wiki/noble-upgrade-architecture>.

Fixes #7332.

noble-migration/Cargo.toml

@@ -5,6 +5,9 @@ edition = "2021"
 
 [dependencies]
 anyhow = "1.0.93"
+env_logger = { version = "0.11.5", features = ["humantime"] , default-features = false }
+log = "0.4.22"
+rand = "0.8.5"
 rustix = { version = "0.38.40", features = ["process"] }
 serde = { version = "1.0.215", features = ["derive"] }
 serde_json = "1.0.132"

noble-migration/files/apt_freedom_press.list

@@ -0,0 +1 @@
+deb [arch=amd64] https://apt.freedom.press noble main

noble-migration/files/sources.list

@@ -0,0 +1,13 @@
+## newer versions of the distribution.
+deb http://archive.ubuntu.com/ubuntu/ noble main
+
+## newer versions of the distribution.
+deb http://archive.ubuntu.com/ubuntu/ noble universe
+
+## Major bug fix updates produced after the final release of the
+## distribution.
+deb http://archive.ubuntu.com/ubuntu/ noble-updates main
+
+### Security fixes for distribution packages
+deb http://security.ubuntu.com/ubuntu noble-security main
+deb http://security.ubuntu.com/ubuntu noble-security universe

noble-migration/files/ubuntu.sources

@@ -0,0 +1,11 @@
+Types: deb
+URIs: http://archive.ubuntu.com/ubuntu/
+Suites: noble noble-updates
+Components: main universe restricted multiverse
+Signed-By: /usr/share/keyrings/ubuntu-archive-keyring.gpg
+
+Types: deb
+URIs: http://security.ubuntu.com/ubuntu/
+Suites: noble-security
+Components: main universe restricted multiverse
+Signed-By: /usr/share/keyrings/ubuntu-archive-keyring.gpg