Remove clang compiler from noble stemcell

[aramprice]

This PR resolves #408, and makes progress on #328

Looking for feedback on changes to the various dpkg lists. These were manually edited by looking at the packages installed after running installing clang as follows:

From a stock ubuntu:noble container, via docker run -it ubuntu:noble bash:

; apt update
; apt upgrade --assume-yes
; apt install --assume-yes build-essential
; dpkg -l > before.txt

;  apt install --fix-broken --no-install-recommends --assume-yes clang
; dpkg -l > after.txt

Additional packages after installing clang

based on diff before.txt after.txt

Items with a clear connection to clang, and part of the original commit in Jammy:

clang
clang-18
libclang-common-18-dev
libclang-cpp18
libclang1-18

libgc1

libllvm18
llvm-18-linker-tools

libobjc-13-dev
libobjc4

Items not part of the original clang commit in Jammy:

libedit2 # not part of original clang commit
libicu74 # not part of original clang commit
libxml2 # not part of original clang commit

[ramonskie]

lgtm