doc: delete mdb_v8 from diagnostic tooling support tiers

PR-URL: #42626
Reviewed-By: Rafael Gonzaga <rafael.nunu@hotmail.com>
Reviewed-By: Darshan Sen <raisinten@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Gerhard Stöbich <deb2001-github@yahoo.de>
Reviewed-By: Michael Dawson <midawson@redhat.com>

Author: tony-go

doc/contributing/diagnostic-tooling-support-tiers.md

@@ -125,7 +125,6 @@ The tools are currently assigned to Tiers as follows:
 | Tool Type | Tool/API Name             | Regular Testing in Node.js CI | Integrated with Node.js | Target Tier |
 | --------- | ------------------------- | ----------------------------- | ----------------------- | ----------- |
 | FFDC      | node-report               | No                            | No                      | 1           |
-| Memory    | mdb\_V8                   | No                            | No                      | 4           |
 | Memory    | node-heapdump             | No                            | No                      | 2           |
 | Memory    | V8 heap profiler          | No                            | Yes                     | 1           |
 | Memory    | V8 sampling heap profiler | No                            | Yes                     | 1           |