tests: Add integration tests for validating SRE Recipe config schema

[Gan-Tu]

The validation mainly relies on the newest JSON Schema (https://json-schema.org) definition, and it works by first converting the YAML config to JSON, and then validate directly on the converted JSON. Added relevant README changes as well.

In order to make decoupling JSON schema easier, I decided to write a custom schema bundling logic for schema "references", since the Python version of the JSON schema validator doesn't support referencing local files well.

[github-actions[bot]]

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[daniel-sanche]

So to make sure I'm reading this correctly: the purpose of this PR is to add a test to ensure recipes are valid by defining the expected JSON schema, and adding a test to check that all recipe YAML conforms to it?

And going forward, if we want to build the recipe codebase (eg, adding actions), we have to adjust the scemas, but when adding future recipes we don't have to touch anything?

Let me know if I have any misconceptions. Thanks!

[Gan-Tu]

So to make sure I'm reading this correctly: the purpose of this PR is to add a test to ensure recipes are valid by defining the expected JSON schema, and adding a test to check that all recipe YAML conforms to it?

And going forward, if we want to build the recipe codebase (eg, adding actions), we have to adjust the scemas, but when adding future recipes we don't have to touch anything?

Let me know if I have any misconceptions. Thanks!

Your understanding is correct. It ensures the YAML schema is followed, but no adjustment needed for new recipes, unless new actions are defined.

[Gan-Tu]

Moved test to CI