encoding/openapi: remove unused code
encoding/openapi: remove unused code

Change-Id: I82a97a4e0d0526c33c587aa680ce7f267e51ac3c
Reviewed-on: https://cue-review.googlesource.com/c/cue/+/5680
Reviewed-by: Marcel van Lohuizen <a22d082192f3ccf984644a4f482781f4c2d65180@golang.org>

cuelang/cue