Update to CKEditor 48

[brianjhanson]

Updates CKEditor to v48, no major changes needed on our end. Only two things worth noting

The scope of the .ck-reset_all-excluded class has been expanded to also include the container wearing that class (e.g. to limit inheritance of font properties).

Because of this, elements of the CKEditor user interface excluded from the CSS reset by the usage of the .ck-reset_all-excluded class may be prone to unexpected styling. Please make sure to verify the visual styling of such UI elements after updating to this version.

I didn't see anything that required updates from us around this

Added support for creating editors and watchdogs using configuration only, without passing a source element or initial data as the first argument. Passing a source element or initial data as the first argument is now deprecated but still supported. Use config.attachTo for ClassicEditor, config.root.element for single-root editors, and config.roots..element for MultiRootEditor. See ckeditor/ckeditor5#19887.

I went ahead and performed this update