More modern tools in the docker image

[mocenigo]

Hello

I have been trying to use

1. TikZ
2. to generate a svg, so I needed pdf2svg
3. and the same fonts as in the spec, so for instance Petrona in the tiki graphs.

This has become quite annoying, so I also migrated to ubuntu 26.04 and I attach as a reference (I had to add a "txt" extension to make GitHub actually load it).

The differences are

1. Used ubuntu 26.04 as an image
2. this gives me also a more recent texlive
3. To actually have proper luatex support, I added texlive-luatex to the runtimeDeps
4. changed libxml2 to libxml2-16
5. Added pdf2svg to the runtimeDeps, so now the workflow can convert pdf to sig and include it in the document
6. removed the asciidoctor-mathematical gem — the latter is incredibly old — and now mathematical is at 1.7.0
7. For sympy, pyyaml, and jsonschema the "pip3 install --no-cache-dir" line is now "pip3 install --no-cache-dir --break-system-packages" - I guess that defining an environment and activating it automatically for asciidoctor is possible but I did not bother much at this stage, sorry.
8. added gems asciidoctor-pdf-mathjax, asciidoctor-mathjax3, asciidoctor-mathml, hanven't tested yet whether they support the stem: macro, but there is a total of TWO instances of it in the entire current RISC-V spec.
9. I have downloaded the Petrona and Montserrat fonts and added the following lines
   RUN mkdir -p /usr/share/fonts/truetype/Petrona/
   COPY /Petrona/* /usr/share/fonts/truetype/Petrona/
   RUN mkdir -p /usr/share/fonts/truetype/Montserrat/
   COPY /Montserrat/* /usr/share/fonts/truetype/Montserrat/
   so I can now use these fonts. This is necessary to make fonts available to luatex, there may be other methods, but I am not a linux expert. The other fonts used in the specification should be ade available as well, but this is a PoC, and did not need top copy them all.

I haven't figured out how to enable ruby v4, which should be much faster since it has now a JIT.

I haven't tried to compile the spec.

Maybe this can be used as a starting point for a more modern image?

ubuntu2604b.txt