docs: reflect removal of ping, logging/setLevel, and notifications/roots/list_changed #3032

Where was this agreed?

Requested by maintainer David Soria Parra as part of preparing the modelcontextprotocol.io documentation for the 2026-07-28 specification release.

Description

The 2026-07-28 spec release removes ping, logging/setLevel, and notifications/roots/list_changed. The debugging and client concepts pages still reference these methods and their anchors.

Files to update:

• docs/docs/tools/debugging.mdx — replace the logging/setLevel advice with the per-request io.modelcontextprotocol/logLevel _meta field and fix the soon-to-vanish anchors
• docs/docs/learn/client-concepts.mdx — rewrite the roots dynamic-update wording (lines 122, 136) without roots/list_changed

Part of the 2026-07-28 release documentation tracking (milestone: 2026-07-28 Specification Release).