fix(release): draft via REST to dodge gh CLI GraphQL tag lag
`gh release create --verify-tag` (and the underlying draft creation)
uses a GraphQL ref lookup that lagged behind the Git Data API we use
to push the tag. Hitting the draft step seconds after tag creation
got us "no matches found for `v1.12.3`" or, without --verify-tag,
an `untagged-*` placeholder release.
Switch to the REST `/releases/generate-notes` + `/releases` POST
endpoints. They consult the same backend that already serves the
freshly-pushed tag, so the draft attaches cleanly to v<version>.
Caught while dispatching v1.12.3.
