feat: enable compiled plugins

[chrisdickinson]

Add extism.CompiledPlugin, which may be provided as the wasm parameter to extism.Plugin.

[chrisdickinson]

(Tests will fail until we cut a new release of extism/extism!)

[zshipko]

From reading through it looks good - I couldn't figure out how to run the tests locally with a custom built extism-sys, but if you were able to confirm these changes then feel free to merge. Otherwise we can just wait until the next libextism release.

[chrisdickinson]

Thanks for the review! I tested via:

~/extism/extism-maturin $ git rev-parse --short HEAD
4db57de

~/extism/extism-maturin $ maturin build -i python3.11
🔗 Found cffi bindings
🐍 Using CPython 3.11 at /opt/homebrew/opt/[email protected]/bin/python3.11 to generate the cffi bindings
📡 Using build options bindings from pyproject.toml
💻 Using `MACOSX_DEPLOYMENT_TARGET=11.0` for aarch64-apple-darwin by default
   Compiling extism v0.0.0+replaced-by-ci (~/extism/runtime)
   Compiling extism-sys v0.0.0+replaced-by-ci (~/extism/extism-maturin)
    Finished `dev` profile [unoptimized + debuginfo] target(s) in 4.00s
💼 Using the existing header at ~/extism/target/header.h
📦 Built wheel to ~/extism/target/wheels/extism_sys-0.0.0+replaced.by.ci-py3-none-macosx_11_0_arm64.whl

~/extism/extism-maturin $ cd ../python-sdk

~/python-sdk $ rm -f uv.lock && uv add --force-reinstall ~/extism/target/wheels/extism_sys-0.0.0+replaced.by.ci-py3-none-macosx_11_0_arm64.whl

~/python-sdk $ uv run python -m unittest discover
.............
----------------------------------------------------------------------
Ran 13 tests in 1.738s

OK

I might run a libextism patch release tomorrow just to boot out those changes.