chore: remove legacy schema validation code

[hoffa]

Issue #, if available

Description of changes

See #3256 (comment), it seems as if recent regression in jsonschema is causing issues with tests. Also #3248 caught RefResolver warnings.

In any case, the entire validator code is unused (removed in #2961), so getting rid of it. Nowadays we do thorough schema tests elsewhere:

serverless-application-model/tests/schema/test_validate_schema.py

Lines 83 to 86 in 8b1b143

	@parameterized.expand(itertools.product(SCHEMA_VALIDATION_TESTS))
	def test_validate_schema(self, testcase):
	obj = yaml_parse(Path(testcase).read_bytes())
	validate(obj, schema=SCHEMA)

Description of how you validated changes

Checklist

• Adheres to the development guidelines
• Add/update transform tests
  • Using correct values
  • Using wrong values
• Add/update integration tests

Examples?

Please reach out in the comments if you want to add an example. Examples will be
added to sam init through aws/aws-sam-cli-app-templates.

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[yan12125]

Thank you very much for this fix. May I expect a new version with this fix in near future?

[hoffa]

@yan12125 Yes, it should roll out in the upcoming weeks. If you need a fix for the jsonschema issue sooner, I'd suggest pinning to an earlier version (I think <4.18, but haven't tested).

[yan12125]

Thank you for the information. However, I cannot decide jsonschema version in our environment. I'm maintaining this Arch Linux package, and jsonschema on Arch Linux is already upgraded to 4.18.3. I will investigate alternative approaches - probably backporting this fix or disabling relevant tests.