Update CI

[mathomp4]

CI is broken. Let's try and fix...

So far: remove pypy@3.9, add pypy@3.11.

We also now have:

warning: The tool.uv.dev-dependencies field (used in /Users/mathomp4/mepo/pyproject.toml) is deprecated and will be removed in a future release; use dependency-groups.dev instead

So I'll update that in pyproject.toml

[mathomp4]

ChatGPT also says:

3. Your wheel packages = ["etc", "src/mepo"] is the big problem
   etc is not a Python package, so Hatch will likely error or silently ignore it.
   For wheels, packages should only describe importable packages/modules.
   If you want etc/ included in the wheel, use force-include.

and it suggests:

[tool.hatch.build.targets.wheel]
packages = ["src/mepo"]

[tool.hatch.build.targets.wheel.force-include]
"etc" = "etc"

but only @pchakraborty knows if this might be correct.