Updated the grafana Test Session link to point to the correct dashboard

What does this MR do and why?

This MR updates the Test session links to grafana dashboard. The previous links were giving a 404 as it was pointing to the wrong link.

Example of the previously wrong link https://gitlab.com/gitlab-org/quality/testcase-sessions/-/issues/71293#link-to-grafana-dashboard-for-run-type-of-e2e-test-on-gdk

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