Remove OpenAI Agents integration

[brianstrauch]

Summary

• remove the bundled OpenAI Agents implementation and its SDK-owned test suite
• retain temporalio[openai-agents] as a forwarding extra that installs temporalio-openai-agents
• preserve the old public temporalio.contrib.openai_agents imports with explicit compatibility modules
• make temporalio.openai_agents the canonical standalone import path
• remove the temporalio.contrib.__getattr__ migration hook
• extend the temporalio package path so editable standalone plugins can be discovered
• remove the dedicated CI step and CODEOWNERS entries for the formerly bundled implementation

This is the SDK half of the OpenAI Agents plugin cutover. The standalone distribution installs under temporalio.openai_agents, so it can coexist with an SDK-bundled temporalio.contrib.openai_agents implementation without sharing files.

Release order

temporalio-openai-agents 1.0.0 is published on PyPI. The two-week dependency age window has passed, and this branch now locks the published package without a per-package override.

1. Prepare OpenAI Agents package cutover ai-integrations#23 was merged, and temporalio-openai-agents 1.0.0 was published through its normal release workflow.
2. The lockfile was regenerated and local validation completed. GitHub CI runs on the updated branch.
3. Merge this PR and publish the Temporal SDK release after review and CI pass.

Migration

Remove the openai-agents extra from the existing Temporal dependency and install the standalone package directly:

# Before
dependencies = [
    "temporalio[openai-agents,otel,pydantic]",
]

# After
dependencies = [
    "temporalio[otel,pydantic]",
]

Remove the brackets if no extras remain. Then install the standalone package:

uv add temporalio-openai-agents

Change application imports to the standalone package:

from temporalio.openai_agents import OpenAIAgentsPlugin

The new import path selects the standalone implementation instead of the SDK-bundled temporalio.contrib.openai_agents implementation.

The forwarding extra and old public imports remain available for compatibility, but direct dependency on temporalio-openai-agents and the temporalio.openai_agents import are the recommended migration.

Validation

Completed on macOS with Python 3.14:

• uv lock --check
• uv sync --all-extras
• poe build-develop
• poe lint
• poe test -s -k openai_agents_compatibility (2 passed)

The full SDK test matrix runs in CI.

[DABH]

Side note from watching this branch's CI: maturin develop --uv now downloads PyPI temporalio==1.33.0 (12.9 MiB) before overwriting it with the local build, because the dev dependency temporalio-openai-agents depends on temporalio[opentelemetry,pydantic]. Tests still import the source tree, so results are fine, but a [tool.uv.sources] override for temporalio (or --no-deps on that install) would save the round trip and avoid a surprise if the PyPI version ever diverges from the tree.

Separately, the test_opentelemetry_safe_detach failures on the macos-arm lanes here are deterministic, not flaky: with the OpenAI Agents suite gone, strands tests (which enable OpenTelemetry's ThreadingInstrumentor) now share an xdist worker with that test and defeat the interceptor's detach guard. Fix in #1911; once it lands and you merge main, those lanes should settle.