No bug: revert D121654 because it will eventually break autoland. r=aki

https://phabricator.services.mozilla.com/D121654 for more context

Differential Revision: https://phabricator.services.mozilla.com/D121722

taskcluster/taskgraph/util/cached_tasks.py

@@ -12,10 +12,8 @@ import six
 
 TARGET_CACHE_INDEX = "{trust_domain}.cache.level-{level}.{type}.{name}.hash.{digest}"
 EXTRA_CACHE_INDEXES = [
-    "{trust_domain}.cache.level-{level}.{type}.{name}.pushdate.{build_date_long}",
-]
-MOZILLA_CENTRAL_ONLY_EXTRA_CACHE_INDEXES = [
     "{trust_domain}.cache.level-{level}.{type}.{name}.latest",
+    "{trust_domain}.cache.level-{level}.{type}.{name}.pushdate.{build_date_long}",
 ]
 
 
@@ -76,13 +74,6 @@ def add_optimization(
     taskdesc["routes"].extend(
         ["index.{}".format(route.format(**subs)) for route in EXTRA_CACHE_INDEXES]
     )
-    if config.params["project"] == "mozilla-central":
-        taskdesc["routes"].extend(
-            [
-                "index.{}".format(route.format(**subs))
-                for route in MOZILLA_CENTRAL_ONLY_EXTRA_CACHE_INDEXES
-            ]
-        )
 
     taskdesc["attributes"]["cached_task"] = {
         "type": cache_type,