Remove stx-release-notes-jobs

The release notes are not updated in this repo and a recent change
in openstack [1] broke the job. This commit removes it.

[1] https://review.opendev.org/c/openstack/openstack-zuul-jobs/+/993658

Closes-bug: 2156935

Change-Id: I452f016a80067496e78aaf74b042a658652cd9a6
Signed-off-by: Victor Romano <victor.gluzromano@windriver.com>

.zuul.yaml

@@ -3,7 +3,6 @@
     templates:
       - publish-stx-docs
       - stx-api-ref-jobs
-      - stx-release-notes-jobs
       - stx-bandit-jobs
     check:
       jobs: