[ci][docker] build py3.14 ray image

[elliot-barn]

Adds CPython 3.14 as a supported target in Ray's CI/release infrastructure: wheel builder, image build pipeline, dependency locks, release-test config schema, and a hello_world_py314 smoke release test.

Follow-up PR carries the _raylet.so runtime fix that makes async actors actually work on cp3.14. This PR enables the build/test plumbing only; without the runtime PR landing first, any release test that exercises async actors will crash on JobSupervisor.

Buildkite image build pipeline

• .buildkite/_images.rayci.yml — adds py314 entries to the base/cuda/slim image matrices so the image-matrix steps emit cp3.14 variants.
• .buildkite/build.rayci.yml — image build + publish steps for ray-py3.14 and ray-extra-py3.14.
• .buildkite/linux_aarch64.rayci.yml — aarch64 base + image build + publish for cp3.14.
• .buildkite/release/build.rayci.yml — anyscale release-test images (raycpubaseextra-testdeps, raycudabaseextra-testdeps, ray-anyscale-cpu-build, ray-anyscale-cuda-build, anyscalecpubuild, anyscalecudabuild) extended to cp3.14. This is what unblocks the prior CI error Step dependencies not found: anyscalecpubuild--python314.
• ci/raydepsets/configs/rayimg.depsets.yaml — declares the cp3.14 depset for the ray image.

Dependency locks (raydepsets)

New cp3.14 lock files generated via raydepsets:

Wheel builder + release-test config

• ci/build/build_wheel.py — SUPPORTED_PYTHON_VERSIONS includes "3.14", so python ci/build/build_wheel.py produces cp314 wheels.
• release/ray_release/schema.json — "3.14" added to the python enum (without this, release-test config validation rejects python: "3.14").
• release/ray_release/config.py — "3.14" added to the BYOD-type allowlist (parallel change to schema.json — both gates the release runner walks before accepting a test).

Release smoke test

• release/release_tests.yaml — adds hello_world_py314 (aws variation only, nightly cadence) that submits a trivial ray.get(hello_world.remote()) job. Uses the same hello_world_compute_config.yaml as the existing hello_world test, just pinned to python: "3.14" and anyscale_sdk_2026: true.

Misc

• docker/base-deps/Dockerfile — bumps libffi (cp3.14's _ctypes build needs the newer ABI).

Verification

• hello_world_py314 release test passes against an image built from this branch

[gemini-code-assist]

Code Review

This pull request adds support for Python 3.14 across various CI and dependency configuration files. However, the review highlights that this addition is premature due to a lack of upstream support for Python 3.14 in critical libraries like PyTorch, TensorFlow, and JAX. Additionally, the newly added python/requirements_compiled_py3.14.txt contains invalid package versions and incorrect environment markers that will lead to immediate build failures and runtime errors.

[gemini-code-assist]

This requirements file contains numerous non-existent or "future" package versions that are not available on PyPI or the specified indices. Examples include torch==2.7.0 (line 2373), numpy==2.3.2 (line 1267), and several packages with futuristic 2026.x versions (e.g., certifi==2026.4.22 on line 284). Additionally, the --find-links URL on line 2 points to a non-existent version. These errors will cause the Docker image build to fail immediately.

[gemini-code-assist]

Adding support for Python 3.14 is premature. Python 3.14 is currently in early alpha development and is not yet supported by critical upstream dependencies such as PyTorch, TensorFlow, and JAX. Furthermore, the Python ABI is not yet stable for this version. Adding it to the build matrix at this stage will result in broken CI builds and non-functional Docker images.

[gemini-code-assist]

Many dependencies in this file (e.g., aim on line 33, array-record on line 120, configspace on line 387) include environment markers such as ; python_version < "3.12". Since this file is intended for Python 3.14, these dependencies will be skipped during installation, which will lead to missing packages and runtime failures in the Ray environment.

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