Remove high-availability Zuul project

The high-availability plugin is already verified using Gerrit-CI.

Change-Id: Ia756d800b2dd3053ebc08679fb2b632ebaf87271
diff --git a/zuul.d/projects.yaml b/zuul.d/projects.yaml
index 556c2ce..a420710 100644
--- a/zuul.d/projects.yaml
+++ b/zuul.d/projects.yaml
@@ -153,12 +153,6 @@
         - gerrit-plugin-build
 
 - project:
-    name: plugins/high-availability
-    check:
-      jobs:
-        - gerrit-plugin-build
-
-- project:
     name: plugins/imagare
     check:
       jobs: