feat: remove obsolete `deno` preview feature (#5372)
Remove obsolete preview feature for Deno Deploy 1.x.
Deno (both CLI and Deploy) work with Prisma Client with any preview
features, and the new ESM client generator makes the support first
class.
Ref:
https://linear.app/prisma-company/issue/ORM-679/get-rid-of-prismaclientdeno-and-previewfeatures-=-deno
