[build] add ray-wheel for ray and ray-cpp, local wheel build scripts

[andrew-anyscale]

adds new Wanda + Dockerfile for building out ray and ray-cpp.

Most of the challenge was in making sure all Wanda pre-req images were built out locally.

build_targets.py declares various Wanda build targets, allowing for easy DEPS setting. It's pretty fragile in terms of naming, but resolves the issue of orchestrating all the builds for local development

Additionally, once we enable building the Ray image, we can easily extend the file for those targets

[gemini-code-assist]

Code Review

This pull request introduces a comprehensive local build system for ray and ray-cpp wheels using Wanda and Docker, which is a significant improvement for local development workflows. The code is well-structured, using Python classes to define build targets and their dependencies, making the system modular and extensible. The inclusion of a Makefile wrapper provides a convenient command-line interface. The test suite for the build targets is thorough and well-written.

I have identified one bug in the wheel extraction logic that would cause failures on non-default architectures, and one critical issue where a required Wanda spec file is missing, which would prevent the ray-cpp wheel from being built. After addressing these points, this will be a solid contribution.

[gemini-code-assist]

The build will fail when trying to build the ray-cpp-wheel target because the specified Wanda spec file ci/docker/ray-cpp-wheel.wanda.yaml is missing from this pull request. Please add this file to the PR.

[gemini-code-assist]

The extract_wheels function hardcodes ARCH_SUFFIX to "" when creating its BuildContext. This will cause an error when trying to extract wheels for a build that used a specific architecture (e.g., aarch64), as the image name will be constructed incorrectly.

The arch_suffix should be passed down from build_wheels and used here. You'll also need to update the call at line 105 to pass arch_suffix:

# in build_wheels()
extract_wheels(python_version, target, out_dir, dry_run, arch_suffix=arch_suffix)

Suggested change

	def extract_wheels(
	python_version: str = "3.10",
	target: str = "ray",
	out_dir: Optional[Path] = None,
	dry_run: bool = False,
	) -> None:
	"""Extract wheels from built images."""
	if out_dir is None:
	out_dir = get_repo_root() / ".whl"
	# Create minimal context just for image_name() calls
	ctx = BuildContext(env={"PYTHON_VERSION": python_version, "ARCH_SUFFIX": ""})
	def extract_wheels(
	python_version: str = "3.10",
	target: str = "ray",
	out_dir: Optional[Path] = None,
	dry_run: bool = False,
	arch_suffix: str = "",
	) -> None:
	"""Extract wheels from built images."""
	if out_dir is None:
	out_dir = get_repo_root() / ".whl"
	# Create minimal context just for image_name() calls
	ctx = BuildContext(env={"PYTHON_VERSION": python_version, "ARCH_SUFFIX": arch_suffix})