ci: avoid triggered-by-schedule and triggered-by-merge builds cancelling each other

[jameslamb]

Contributes to rapidsai/build-planning#278

Today, merging a PR while the nightly build is in progress can lead to it being cancelled.
This updates CI configurations to prevent that.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Path: .coderabbit.yaml

Review profile: CHILL

Plan: Enterprise

Run ID: a184c910-5c35-4bb0-81ef-287559d5a2ef

📥 Commits

Reviewing files that changed from the base of the PR and between 1d3dafe and f57e6d0.

📒 Files selected for processing (1)

• .github/workflows/build.yaml

Included review availability: Your plan provides up to 12 included reviews per hour; 9 remain after this review.

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📝 Walkthrough

Summary by CodeRabbit

• Chores
  • Improved workflow run management by separating concurrent builds according to their selected build type.

Walkthrough

The build workflow now separates concurrency groups by build_type. Unspecified dispatches use branch as the default value.

Changes

Build workflow concurrency

Layer / File(s)	Summary
Include build type in concurrency key .github/workflows/build.yaml	The concurrency group key now includes the workflow-dispatch build_type input and defaults to branch when unspecified.

Estimated code review effort: 1 (Trivial) | ~2 minutes

Merge Risk: ⚪ Minimal · up to f57e6

This localized CI configuration change prevents scheduled and merge-triggered builds from cancelling each other, with no actionable merge-blocking risk remaining after normal checks and review.

Suggested reviewers: bdice, jolorunyomi, paul-aiyedun

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Title check	✅ Passed	The title clearly describes the CI concurrency change that prevents scheduled and merge-triggered builds from cancelling each other.
Description check	✅ Passed	The description directly explains the CI cancellation problem and the purpose of the configuration change.

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests

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_{Comment @coderabbitai help to get the list of available commands.}

[jameslamb]

/merge