xlibswrapper is removed from `Toolchain/serenity.nix` as it is a
wrapper package and has been deprecated. We don't use it in the build
anyway.
This fixes#19286
During the build, python3 is required so we add `python3` as a build
dependency.
Nix (nixpkgs) have updated a while back how the e2fsprogs derivation
works and now fuse2fs wasnt being installed with it. It is now needed to
add a new derivation (package) to the dependency list: "fuse2fs". This
fixes the Meta/serenity.sh script not finding the fuse2fs binary for
rootless image building :^)
* x11 package name has changed to xlibsWrapper.
* texinfo is necessary for Makeinfo.
* e2fsprogs was recenty fixed on nicpkgs to include fuse2fs to mount
serenity images without root access but it needed some configuration.
Moves the nix script to setup the build environment from Documentation
into the Toolchain as a callable script. I also modified the script
to accept a "pkgs" argument to make it easy to override the nixpkgs
version from the command-line when calling the script.
