Related Issues/PRs

What changes are proposed in this pull request?

Migrates 19 lightweight automation jobs across 16 workflow files from ubuntu-latest to ubuntu-slim runners. GitHub announced ubuntu-slim runners in October 2025 as a cost-efficient alternative for lightweight workloads (1 vCPU, 5GB RAM, 15min max runtime, ~75% cheaper in private repos).

Jobs migrated (all timeout ≤10 minutes):

• PR/Issue automation: labeling, advice comments, cherry-pick warnings, closing PRs
• Workflow orchestration: cancel, rerun, trigger cross-version tests
• Autoformat automation: comment validation, status updates, code push
• Release automation: release note validation, post-merge tasks
• Team automation: review requests, maintainer checks
• Monitoring: test visualization via GitHub API

Jobs excluded (heavyweight operations):

• requirements.yml skinny job - runs actual tests
• preview-docs.yml - Netlify deployment with large artifacts
• protos.yml - protobuf generation and tests
• uv.yml - dependency updates and PR creation

All migrated jobs are simple scripting/API tasks well within ubuntu-slim's resource constraints.

How is this PR tested?

• Existing unit/integration tests
• New unit/integration tests
• Manual tests

Validated YAML syntax for all 16 modified workflow files. Changes are minimal (only runs-on field updated). Pre-commit hooks passed.

Does this PR require documentation update?

• No. You can skip the rest of this section.
• Yes. I've updated:
  • Examples
  • API references
  • Instructions

Release Notes

Is this a user-facing change?

• No. You can skip the rest of this section.
• Yes. Give a description of this change to be included in the release notes for MLflow users.

What component(s), interfaces, languages, and integrations does this PR affect?

Components

• area/tracking: Tracking Service, tracking client APIs, autologging
• area/models: MLmodel format, model serialization/deserialization, flavors
• area/model-registry: Model Registry service, APIs, and the fluent client calls for Model Registry
• area/scoring: MLflow Model server, model deployment tools, Spark UDFs
• area/evaluation: MLflow model evaluation features, evaluation metrics, and evaluation workflows
• area/gateway: MLflow AI Gateway client APIs, server, and third-party integrations
• area/prompts: MLflow prompt engineering features, prompt templates, and prompt management
• area/tracing: MLflow Tracing features, tracing APIs, and LLM tracing functionality
• area/projects: MLproject format, project running backends
• area/uiux: Front-end, user experience, plotting, JavaScript, JavaScript dev server
• area/build: Build and test infrastructure for MLflow
• area/docs: MLflow documentation pages

How should the PR be classified in the release notes? Choose one:

• rn/none - No description will be included. The PR will be mentioned only by the PR number in the "Small Bugfixes and Documentation Updates" section
• rn/breaking-change - The PR will be mentioned in the "Breaking Changes" section
• rn/feature - A new user-facing feature worth mentioning in the release notes
• rn/bug-fix - A user-facing bug fix worth mentioning in the release notes
• rn/documentation - A user-facing documentation change worth mentioning in the release notes

Should this PR be included in the next patch release?

• Yes (this PR will be cherry-picked and included in the next patch release)
• No (this PR will be included in the next minor release)

💡 You can make Copilot smarter by setting up custom instructions, customizing its development environment and configuring Model Context Protocol (MCP) servers. Learn more Copilot coding agent tips in the docs.