Remove CANVAS_ZEITWERK check in aaa_sfu_misc
Remove CANVAS_ZEITWERK check in aaa_sfu_misc

This is no longer needed as Zeitwerk is now the only autoloader.

Related upstream commits where the constant was removed:

* 4253bed58b54e4fb3ad2f7262b121061d548645c
* f8e9fdc35c2b5112501fe58371674aae692e07cf

sfu/canvas-lms,sfu/canvas-lms,sfu/canvas-lms,sfu/canvas-lms,sfu/canvas-lms,sfu/canvas-lms,sfu/canvas-lms