tests: SAM json schema test checks old goformation schema

## Problem

in these tests: https://github.com/aws/aws-toolkit-vscode/blob/29d4338abea47e503f4d606b9382d1ecd3fd4d4b/src/integrationTest/schema/schema.test.ts#L22

the `getCITestSchemas()` function still uses the old json-schema: https://github.com/awslabs/goformation

## Solution

update the tests to use the new json-schema:

https://raw.githubusercontent.com/aws/serverless-application-model/main/samtranslator/schema/schema.json

Start in src/integrationTest/schema/schema.test.ts around getCITestSchemas(), where the tests still reference the goformation JSON schema. Replace that schema source with the SAM schema at the provided aws/serverless-application-model URL. Done means the schema tests use the new source and pass.

Written by the indexing model from the issue text.