Remove unnecessary warn() in JWT validation code

[nickcatal]

There is a warn() that indicates that authenticate_request should only be used for backend API requests.

This is showing up in various logs in my app (tests, access logs, etc) without providing insight that couldn't be determined from just reading the project's documentation.

[PaoloSalta]

Updated to 1.8.0, still getting the warn notice

[nickcatal]

@simplesagar @speakeasybot @tmilewski Can one of y'all merge this in and bump the version at your earliest convenience?

[tmilewski]

@nickcatal I have merged this; however, I can't push a new release until additional (unrelated) testing is completed. Hopefully, it will not take too long, though!