Package-and-test failure discussions are being opened on security

Problem

In gitlab-org/gitlab!112367 (merged), we added a new CI job so when a e2d:package-and-test-ee job fails on a stable branch, a discussion is opened pinging the MR author.

The problem is, we are seeing these discussions opened on MRs targeting non-canonical repos (example).

Solution

Update the CI rules so the notify-package-and-test-failure job only runs on canonical.

The bug exists in 15-11-stable-ee and 15-10-stable-ee, so we should backport the fix to those branches.

Code references

• notify-package-and-test-failure job
• Pipeline rules for that job