feat: Automated testing

[Laikulo]

Adds linting with ruff and klippy's import test and test harness with a simple config.

Summary by Sourcery

This pull request introduces automated testing via a new GitHub Actions workflow. It includes linting with Ruff, Klippy's import test, and a test harness with a simple configuration for running smoke tests.

• CI:
  • Added a GitHub Actions workflow for smoke tests, including linting with Ruff and Klippy's import test.
  • Configured matrix strategy for testing with multiple Klipper repositories.
  • Set up steps for checking out repositories, installing dependencies, building Klipper, and running tests.
• Tests:
  • Introduced a test harness with a simple configuration for Klippy tests.

[sourcery-ai]

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[sourcery-ai]

Hey @Laikulo - I've reviewed your changes and they look great!

Here's what I looked at during the review

• 🟡 General issues: 3 issues found
• 🟢 Security: all looks good
• 🟢 Testing: all looks good
• 🟢 Complexity: all looks good
• 🟢 Documentation: all looks good

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[Laikulo]

@sourcery-ai review

[sourcery-ai]

We have skipped reviewing this pull request. It looks like we've already reviewed the commit e856ec5 in this pull request.

[Frix-x]

Hello,

Thank you very much for this PR ! It's actually something that I wanted to start working on (Klipper tests and also adding a bit of unit testing into S&T). That's a very good starting point!

I'll merge it :)