chore(ci): removed redundant teams notification

GitHub already emails the triggering actor on workflow failure, and this
covers scheduled runs as well. The Teams workflow duplicated that signal
into a channel that is not monitored, while producing roughly 4300 runner
starts per month for at most 234 actual messages. Around 80 percent of
those runs were triggered by the workflow observing its own completion,
because the workflow_run filter matched all workflows including itself.

The reusable workflow, composite action and configuration remain
available in bauer-group/automation-templates.

Author: karlspace