Re-enable zuultrigger test

This gets both running again, but the second fails because of a
behavior change in v3 which should be addressed separately.

Story: 2000773
Task: 3422

Change-Id: I3d0e7268304e97fa611f70706e15212952aa3c62
diff --git a/tests/fixtures/config/zuultrigger/project-change-merged/main.yaml b/tests/fixtures/config/zuultrigger/project-change-merged/main.yaml
new file mode 100644
index 0000000..a22ed5c
--- /dev/null
+++ b/tests/fixtures/config/zuultrigger/project-change-merged/main.yaml
@@ -0,0 +1,6 @@
+- tenant:
+    name: tenant-one
+    source:
+      gerrit:
+        config-repos:
+          - common-config