Switch all workflows to ubuntu-slim except GitOps

[pofl]

Type of Change

• Bugfix
• Enhancement / new feature
• Refactoring
• Documentation

Description

• https://github.blog/changelog/2025-10-28-1-vcpu-linux-runner-now-available-in-github-actions-in-public-preview/

These runners have one vCPU and 5 GBs RAM. When using these runners, your actions workflows execute inside of a container rather than a dedicated VM instance, enabling cost-effective, performant execution of automation tasks across GitHub. Each container provides hypervisor level 2 isolation, and the container is automatically decomissioned when a job is completed. Jobs that use this runner type are limited to 15 minutes of execution time. Jobs exceeding this limit will be terminated and fail.

If you think any actions should not run in this slim version please flag it. GitOps comes to mind because building Dockerfiles might be heavy.

Checklist

• Add relevant labels (for example type of change or patch/minor/major)
• Make sure not to introduce some mistakes
• Update documentation
• Review the Contributing Guideline and sign CLA
• Reference relevant issue(s) and close them after merging

[stefanmeschke]

I wouldn't use the slim thing here since this is on the release production path and therefore time to market will be decreased when change this.

[pofl]

To my intuition this shouldn't become slower. The release-drafter action is a nodejs action which means it runs single-threaded anyway. So the switch to 1vCPU shouldn't matter 🤔 ?

If ubuntu-slim runs in a container instead of a VM we might even experience faster cold starts 🤔

This line of thinking applies to all actions you commented on.
Wdyt?

[stefanmeschke]

This sounds reasonable. 👍
One thought: NodeJS allows spawning child processes which are then decoupled from the parent event loop and therefore the assumption "it's nodejs it will def. only use one CPU" is not correct.

[stefanmeschke]

We need to monitor this change ofc. 😊

From my point of view there are labels missing on this PR in order to mark this PR as major change etc.

[pofl]

Dear reviewers, thank you for the approvals. In one of our repos I switched to the slim-runner for the Linter. That made the execution time explode. This reassured me in that if we merge this PR we should keep a close eye on stuff.

My capacity is limited and I personally would not like to pick this battle right now. Does anybody want to take the over here? Maybe @sbmars?

[sbmars]

@pofl I can take this over. Maybe @soemo likes to support me? 👓👓