`arm-android/Dockerfile` is based on the now outdated Ubuntu 23.04

[rami3l]

Hi there!

Since a while ago, Rustup's CI workflow has been failing due to the Android job's aborting (rust-lang/rustup#4070 (comment), rust-lang/rustup#4098 (comment)) with the following error message:

#5 0.935 E: The repository 'http://archive.ubuntu.com/ubuntu lunar-updates Release' no longer has a Release file.

... and I believe that it's caused by an outdated base image for which the apt repository is no longer online:

rust/src/ci/docker/host-x86_64/arm-android/Dockerfile

Line 1 in 39cb338

FROM ubuntu:23.04

Are there any concerns regarding a potential bump to an LTS such as 24.04? I can do this myself if you think that's okay :)