Remove plugins/task job as it defines its own job

In Change-Id: I4a06f9fec0 the task plugin defines a job for itself since
it has some unique node requirements.

Change-Id: Ied45251859da094f72aee02e66464bd9d634868a
diff --git a/zuul.d/projects.yaml b/zuul.d/projects.yaml
index 8cbceb4..5652c25 100644
--- a/zuul.d/projects.yaml
+++ b/zuul.d/projects.yaml
@@ -303,12 +303,6 @@
         - gerrit-plugin-build
 
 - project:
-    name: plugins/task
-    check:
-      jobs:
-        - gerrit-plugin-build
-
-- project:
     name: plugins/uploadvalidator
     check:
       jobs: