Dynamic Registration Configuration Endpoint does not send openid under scopes_supported

[lboecken]

Summary:

The Dynamic Registration spec requires that the LMS have openid listed as one of the scopes_supported.
This is currently not being sent.

Steps to reproduce:

1. Make GET request to OIDC Configuration Endpoint
2. Response does not include openid under scopes_supported key

Expected behavior:

That openid is one of the scopes_supported

Actual behavior:

The openid scope is not included in the scopes_supported list.

Additional Notes

canvas-lms/app/controllers/security_controller.rb

Line 111 in f608fbf

scopes_supported: TokenScopes::LTI_SCOPES.keys,

I believe this is the relevant line where this information comes from.