refactor: makefile cleanup

[houtanb]

Some Makefiles use Procfile and some use Dockerfile to deploy.

The Dockerfiles are using Python 3.12 but most (if not all) of the code can run with Python 3.14. Update to Python 3.14, potentially simplify to use Procfile

[nikbpetrov]

@houtanb but we simplify to Dockerfiles, no? It's a few lines more verbose but we have more control. As far as I understand with Procfile, google decides what to deploy in terms of sys packages (so we don't get control over that), so git is not possible.

Does it actually matter whether we use Dockerfile or Procfile? Latter is not obvious to me, less controlled, while former is more flexible/portable. WDYT?

p.s. hehe, w/ 3.14 the default buildpack is uv