doc: delete heapdump from diagnostic tooling support tiers

PR-URL: nodejs/node#42783
Reviewed-By: Richard Lau <rlau@redhat.com>
Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: Darshan Sen <raisinten@gmail.com>
Reviewed-By: Tobias Nießen <tniessen@tnie.de>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>

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    | node-heapdump             | No                            | No                      | 2           |
 | Memory    | V8 heap profiler          | No                            | Yes                     | 1           |
 | Memory    | V8 sampling heap profiler | No                            | Yes                     | 1           |
 | AsyncFlow | Async Hooks (API)         | ?                             | Yes                     | 1           |