Generate Layout 2020 regression report more than once

etc/taskcluster/decision_task.py

@@ -265,7 +265,8 @@ def layout_2020_regressions_report():
         )
         .with_index_and_artifacts_expire_in(log_artifacts_expire_in)
         .with_artifacts("/repo/tests/wpt/reftests-report/report.html")
-        .find_or_create("layout-2020-regressions-report")
+        .with_index_at("layout-2020-regressions-report")
+        .create()
     )
 
 def macos_unit():

etc/taskcluster/decisionlib.py

@@ -157,6 +157,10 @@ def __init__(self, name):
 
     with_extra = chaining(update_attr, "extra")
 
+    def with_index_at(self, index_path):
+        self.routes.append("index.%s.%s" % (CONFIG.index_prefix, index_path))
+        return self
+
     def with_treeherder_required(self):
         self.treeherder_required = True
         return self
@@ -291,7 +295,7 @@ def find_or_create(self, index_path):
             if e.status_code != 404:  # pragma: no cover
                 raise
             if not CONFIG.index_read_only:
-                self.routes.append("index.%s.%s" % (CONFIG.index_prefix, index_path))
+                self.with_index_at(index_path)
             task_id = self.create()
 
         SHARED.found_or_created_indexed_tasks[index_path] = task_id