CI: Reduce workflow overhead

[kevinjqliu]

Grouping a few changes together in this PR. Overall, this helps improve CI and merge queue.

• Change max_entries_to_build from 1 to 2. This allows merge queue to run in parallel
• Don't install extra dependencies for docs-serve and docs-build
• Move a bunch of os to run on ubuntu-slim. Hopefully this will reduce contention waiting for runner
• Add concurrency setting to cancel redundant runs in the same PR

[Copilot]

🔵 Needs a closer look

The dependency-heavy integration report may exceed the ubuntu-slim 15-minute job limit and block the required gate.

Pull request overview

Reduces CI and merge-queue overhead through lighter documentation dependencies, slimmer runners, concurrency cancellation, and parallel queue builds.

Changes:

• Restricts documentation commands to the docs dependency group.
• Moves lightweight jobs to ubuntu-slim and cancels redundant PR runs.
• Increases merge-queue build parallelism from 1 to 2.

File summaries

File	Summary
Makefile	Limits documentation commands to docs dependencies.
.github/workflows/zizmor.yml	Adds workflow concurrency controls.
.github/workflows/svn-build-artifacts.yml	Moves artifact merging to a slim runner.
.github/workflows/stale.yml	Moves stale processing to a slim runner.
.github/workflows/python-release.yml	Moves validation jobs to slim runners.
.github/workflows/python-release-docs.yml	Moves documentation release work to a slim runner.
.github/workflows/python-integration.yml	Moves selected integration jobs to slim runners; the dependency-heavy report job may exceed the 15-minute limit.
.github/workflows/python-ci.yml	Moves the aggregate gate to a slim runner.
.github/workflows/pypi-build-artifacts.yml	Moves artifact merging to a slim runner.
.github/workflows/nightly-pypi-build.yml	Moves version setup to a slim runner.
.github/workflows/license_check.yml	Adds workflow concurrency controls.
.github/workflows/codeql.yml	Adds concurrency controls and a slim runner.
.github/workflows/check-md-link.yml	Adds workflow concurrency controls.
.github/workflows/asf-allowlist-check.yml	Adds concurrency controls and a slim runner.
.asf.yaml	Allows two merge-queue entries to build concurrently.

Review details

Suppressed comments (1)

.github/workflows/python-integration.yml:155

• ubuntu-slim has a hard 15-minute job limit, but this job performs a full uv sync --group dev (including heavyweight development dependencies such as PySpark) before generating the report. A cold-cache run can hit that limit and fail the required python-integration-required gate; keep this dependency-heavy report on a full runner, or reduce the install to only the report's dependencies before moving it to slim.

    runs-on: ubuntu-slim

• Files reviewed: 15/15 changed files
• Comments generated: 0
• Review effort level: Lite

---

💡 Add a code-review agent skill or configure MCP servers for context-aware, tailored reviews. Learn more in the docs.

[rambleraptor]

Thanks for doing this! Excited to see better CI performance, especially on the merge queue.