chore: deprecate "fix CC slowness" feature

The bug has been fixed in the Community Console as per
https://support.google.com/s/community/forum/51488989/thread/269560789/message/277336217.

In the medium term we should remove the feature code from the codebase
once we're sure it won't be needed anymore.

Change-Id: I91715238df8fbe73800885209a28c15c29b703b3
diff --git a/src/features/fixCCSlowness/fixCCSlowness.feature.ts b/src/features/fixCCSlowness/fixCCSlowness.feature.ts
index 5703311..ef5ed2e 100644
--- a/src/features/fixCCSlowness/fixCCSlowness.feature.ts
+++ b/src/features/fixCCSlowness/fixCCSlowness.feature.ts
@@ -4,6 +4,11 @@
 import RemoveUserAbuseEventsFromDataStartupScript from './scripts/removeUserAbuseEventsFromDataStartup.script';
 
 // This feature also has an associated response modifier.
+
+/**
+ * @deprecated This feature has been deprecated. Its code will soon be removed
+ * once we're sure the feature won't come back.
+ */
 export default class FixCCSlownessFeature extends Feature {
   public readonly scripts: ConcreteScript[] = [
     RemoveUserAbuseEventsFromDataStartupScript,