Bug 1869541 - Disable mozperftest xpcshell tests. r=aglavic,perftest-reviewers DONTBUILD

This patch disables the mozperftest http3 test, because of some failures with xpcshell, and/or the mozperftest-xpcshell integration.

Differential Revision: https://phabricator.services.mozilla.com/D196175

taskcluster/ci/perftest/linux.yml

@@ -154,7 +154,8 @@ http3:
         symbol: perftest(http3)
     attributes:
         batch: false
-        cron: true
+        # Disabled due to bug 1849400
+        cron: false
     run:
         command: >-
             mkdir -p $MOZ_FETCHES_DIR/../artifacts &&

taskcluster/ci/perftest/macosx.yml

@@ -117,7 +117,8 @@ http3:
         symbol: perftest(http3)
     attributes:
         batch: false
-        cron: true
+        # Disabled due to bug 1849400
+        cron: false
     run:
         command: >-
             mkdir -p $MOZ_FETCHES_DIR/../artifacts &&