[Chore] Remove the archived meshery-tanzu-sm adapter page from Meshery Docs

Summary

meshery-extensions/meshery-tanzu-sm has been archived since 2023, but its adapter documentation page is still published on the docs site. This issue covers clearing what remains.

The adapter repository is read-only, so this cleanup has no counterpart issue there. One issue per adapter; sibling issues are linked in a comment below.

Meshery Docs

• Delete docs/content/en/extensions/adapters/tanzu-sm/index.md and docs/content/en/extensions/adapters/tanzu-sm/images/tanzu.svg — the page documents an adapter that has been archived for three years

No references remain in Meshery Server, Meshery UI, mesheryctl or the install artifacts (verified).

Out of scope

The MeshType GraphQL enum value TANZU stays; dropping enum values is a breaking API change requiring make graphql-build.

Note

The site repositories still advertise this adapter with a dead link; that is covered in meshery/meshery.io#2987 and layer5io/layer5#8075.