chore(auth): remove dead code related to /certificate/sign

Author: toufali

packages/fxa-auth-server/config/index.ts

@@ -2281,12 +2281,6 @@ const convictConf = convict({
       format: String,
     },
   },
-  certificateSignDisableRolloutRate: {
-    default: 0,
-    doc: 'Rollout rate for disabling certificate signing, in the range 0 .. 1',
-    env: 'CERTIFICATE_SIGN_DISABLE_ROLLOUT_RATE',
-    format: Number,
-  },
   cms: {
     enabled: {
       default: false,

packages/fxa-auth-server/lib/metrics/events.js

@@ -59,7 +59,6 @@ const IGNORE_ROUTE_FLOW_EVENTS_FOR_PATHS = new Set([
   '/account/devices',
   '/account/profile',
   '/account/sessions',
-  '/certificate/sign',
   '/password/forgot/status',
   '/recovery_email/status',
   '/jwks',

packages/fxa-auth-server/lib/routes/oauth/token.js

@@ -904,7 +904,7 @@ module.exports = ({ log, oauthDB, db, mailer, devices, statsd, glean }) => {
           ) {
             // For desktop, the 'service' parameter for this event gets
             // special-cased to 'sync' so that it matches its pre-oauth
-            // `/certificate/sign` event.
+            // `/certificate/sign` event. (Note: `/certificate/sign` is now removed.)
             // ref: https://github.com/mozilla/fxa/pull/6581#issuecomment-702248031
             // Otherwise, for mobile browsers, just use the existing client ID
             // to service name mapping used in the metrics code (see the