Remove the Auto Tests Generators

They weren't used by any Tempest test.

Change-Id: Iaf64f21e779ff089ca4eb4049a826049ea4173de
diff --git a/releasenotes/notes/remove-negative-test-generator-1653f4c0f86ccf75.yaml b/releasenotes/notes/remove-negative-test-generator-1653f4c0f86ccf75.yaml
new file mode 100644
index 0000000..a734d15
--- /dev/null
+++ b/releasenotes/notes/remove-negative-test-generator-1653f4c0f86ccf75.yaml
@@ -0,0 +1,4 @@
+---
+upgrade:
+  - The Negative Tests Generator has been removed (it was not used by any
+    Tempest tests).