ci(test.yml): migrate runners from ubuntu 24.04 to 26.04

[mdevolde]

ci(test.yml): migrate runners from ubuntu 24.04 to 26.04

Why the pull request was made

To keep up to date CI's runners.

Summary of changes

• Change versions of runners from ubuntu 24.04 to ubuntu 26.04.
• Remove setup-python action because we can set up Python with setup-uv.
• Move config actions (setup-uv, setup-java) before checkout action (no need to clone the repo before tools config).
• Set persist-credentials to false for checkout actions (useless because these tokens are "read-only", but good practice, especially if we perform some changes in the future with new permissions).

Screenshots (if appropriate):

Not applicable.

How has this been tested?

Not applicable.

Resources

Runners: https://github.com/actions/runner-images

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation update (changes to documentation only)
• Refactor / code style update (non-breaking change that improves code structure or readability)
• Tests / CI improvement (adding or updating tests or CI configuration only)
• Other (please describe):

Checklist

• Followed the project's contributing guidelines.
• Updated any relevant tests.
• Updated any relevant documentation.
• Added comments to your code where necessary.
• Formatted your code, run the linters, checked types and tests.