Improve devcontainer startup times

[trxcllnt]

This PR builds and publishes devcontainers to ghcr.io and uses the new images to improve CI and local devcontainer startup times.

In rapidsai/devcontainers, devcontainer startup times went from 3m28s to 34s.

Contributes to rapidsai/build-planning#280.

[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: accdb0fc-d494-4a82-b981-cc74c8bbbe6a

📥 Commits

Reviewing files that changed from the base of the PR and between 3cd0279 and 38ac62a.

📒 Files selected for processing (5)

• .devcontainer/cuda12.9-conda/devcontainer.json
• .devcontainer/cuda12.9-pip/devcontainer.json
• .devcontainer/cuda13.2-conda/devcontainer.json
• .devcontainer/cuda13.2-pip/devcontainer.json
• .github/workflows/build.yaml

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📝 Walkthrough

Summary by CodeRabbit

• Chores
  • Optimized development container build performance by adding caching configuration.
  • Automated the building and publishing of development containers in the CI/CD pipeline.

Walkthrough

This pull request adds Docker build cache configuration to four devcontainer variants and introduces a GitHub Actions workflow job to build and push these devcontainers to GHCR. All four devcontainers (CUDA 12.9/13.2 with conda/pip) follow the same pattern of specifying a cacheFrom image source, and a new workflow job orchestrates the build and push operations.

Changes

Devcontainer Cache and Workflow

Layer / File(s)	Summary
Devcontainer cache configuration .devcontainer/cuda12.9-conda/devcontainer.json, .devcontainer/cuda12.9-pip/devcontainer.json, .devcontainer/cuda13.2-conda/devcontainer.json, .devcontainer/cuda13.2-pip/devcontainer.json	All four devcontainer configurations add cacheFrom arrays pointing to corresponding GHCR images (26.08-cuda12.9-conda, 26.08-cuda12.9-pip, 26.08-cuda13.2-conda, 26.08-cuda13.2-pip) to enable Docker build cache reuse.
Devcontainer build and push workflow .github/workflows/build.yaml	New devcontainers job in the build workflow calls a reusable workflow with packages: write permissions and push: true, triggering builds for CUDA 12.9 and 13.2 with secrets inherited.

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~10 minutes

Suggested reviewers

• msarahan
• KyleFromNVIDIA

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title directly describes the main change—improving devcontainer startup times through build caching, which is the primary objective of the changeset.
Description check	✅ Passed	The description is directly related to the changeset, explaining the purpose of building and publishing devcontainer images to improve startup times.
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.

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✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests

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[trxcllnt]

/merge