Enable WPT in Linux taskcluster CI.

etc/taskcluster/decision_task.py

@@ -22,9 +22,6 @@ def main(task_for):
         # This local variable shadows the module-level function of the same name.
         android_x86_wpt = android_x86_release
 
-        # Implemented but disabled for now:
-        linux_wpt = lambda: None  # Shadows the existing top-level function
-
         all_tests = [
             linux_tidy_unit_docs,
             windows_unit,
@@ -100,7 +97,6 @@ def main(task_for):
 def mocked_only():
     windows_release()
     android_x86_wpt()
-    linux_wpt()
     decisionlib.DockerWorkerTask("Indexed by task definition").find_or_create()