refactor: Replace ubuntu-latest with ubuntu-slim in lightweight workflows

[Copilot]

Reduces runner startup time and resource consumption by migrating 13 lightweight workflows from ubuntu-latest to ubuntu-slim.

Changes

• Workflows updated (14 job instances across 13 files):
  • auto-assign-pr.yml
  • codeql-analysis.yml
  • crowdin-per-language.yml
  • crowdin.yml
  • generate-doc.yml
  • github-projects-ventilation.yml
  • label.yml
  • merge-conflict-autolabel.yml
  • pr_actions.yml (2 jobs)
  • release-please.yml
  • semantic-pr.yml
  • top-issues.yml
  • translation-check.yml

These workflows run simple automation tasks (labeling, PR validation, project management) that don't require the full ubuntu-latest environment.

  jobs:
    assign-author:
      name: 'Pull request assignment'
-     runs-on: ubuntu-latest
+     runs-on: ubuntu-slim

Original prompt

Replace ubuntu-latest with ubuntu-slim across all listed GitHub Actions workflows to reduce runner startup time and resource consumption. Do not replace for complex workflows that may require a lot of memory. Below a list of workflows that are definitely safe (from the openfoodfacts-server, names and workflows may vary based on the repo where we're running this refactor task)

auto-assign-pr.yml
codeql-analysis.yml
crowdin-per-language.yml
crowdin.yml
generate-doc.yml
github-projects-ventilation.yml
label.yml
merge-conflict-autolabel.yml
pr_actions.yml
release-please.yml
semantic-pr.yml
top-issues.yml
translation-check.yml

---

💬 We'd love your input! Share your thoughts on Copilot coding agent in our 2 minute survey.

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud