Ignore unknown key "$schema" in schema validation #11182
Description
Following #11040 / #11045, I now get Config contains unrecognized setting "$schema" in a few projects, including typeshed.
Whilst it's true that The pyright VS Code extension ships with a JSON schema for "pyrightconfig.json",, that doesn't work for config files names slightly differently or if not specifically using VSCode w/ Pylance.
That is easy to solve by explicitly setting the schema with $schema, but that now prints a warning.
Examples of config files named differently (for additional tests that can't all be configured in 1 file):
- https://github.com/python/typeshed/blob/90d855985be5aae9bc76e77b0f3d4b6738c38347/pyrightconfig.testcases.json#L2
- https://github.com/python/typeshed/blob/90d855985be5aae9bc76e77b0f3d4b6738c38347/pyrightconfig.stricter.json#L2
- https://github.com/python/typeshed/blob/90d855985be5aae9bc76e77b0f3d4b6738c38347/pyrightconfig.scripts_and_tests.json#L2
- https://github.com/Avasam/pywin32/blob/957453619183b2a9df98872066a1a15953cada05/pyrightconfig.adodbapi.json#L2