Bump authlib min version to 1.7.1

[yvaishalirao (yvaishalirao)]

Fixes #2242

authlib 1.7.0 raises an AuthlibDeprecationWarning for authlib.jose on import, even though this repo only uses authlib.integrations.httpx_client.OAuth2Client and never touches authlib.jose directly. It's an authlib-side import chain issue, fixed upstream in 1.7.1.

Bumped the authlib floor in requirements-schemaregistry.txt and requirements-examples.txt from >=1.0.0 to >=1.7.1.

Verified tests/schema_registry/_sync/test_bearer_field_provider.py and the async counterpart still pass unchanged against 1.7.1.

[confluent-cla-assistant]

🎉 All Contributor License Agreements have been signed. Ready to merge.
✅ yvaishalirao
_{Please push an empty commit if you would like to re-run the checks to verify CLA status for all contributors.}

[Robert Yokota (rayokota)]

/sem-approve

[Robert Yokota (rayokota)]

/sem-approve

[yvaishalirao (yvaishalirao)]

Hi Robert Yokota (@rayokota) , it looks like the Semaphore job has failed multiple times due to what appears to be a CI issue rather than a code change. Would you mind rerunning the failed workflow when you have a chance? Thanks