doc: remove appmetrics from tierlist

PR-URL: #43608 Reviewed-By: Beth Griggs <bgriggs@redhat.com> Reviewed-By: Michael Dawson <mhdawson@ibm.com> Reviewed-By: Richard Lau <riclau@uk.ibm.com> Reviewed-By: Gireesh Punathil <gpunathi@in.ibm.com> Reviewed-By: Darshan Sen <raisinten@gmail.com> Reviewed-By: Rafael Gonzaga <rafael.nunu@hotmail.com> Reviewed-By: Gerhard St<C3><B6>bich <deb2001-github@yahoo.de>

Author: tony-go

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

@@ -134,5 +134,4 @@ The tools are currently assigned to Tiers as follows:
 | Debugger | Command line Debug Client | ? | Yes | 1 |
 | Tracing | trace\_events (API) | No | Yes | 1 |
 | Tracing | trace\_gc | No | Yes | 1 |
-| F/P/T | appmetrics | No | No | ? |
 | M/T | eBPF tracing tool | No | No | ? |