## Changes
This PR removes the dependency to the `databricks-sdk-go/openapi`
package by copying the struct and functions that are needed in a new
`schema/spec.go` file.
The reason to remove this dependency is that it is being deprecated.
Copying the code in the `cli` repo seems reasonable given that it only
uses a couple of very small structs.
## Tests
Verified that CLI code can be properly generated after this change.