Create trivy-all-slack.yml

[zickau]

Commit text: workflow file for slack messages after weekly trivy scan, project context IDunion (Germany)

This file was created to get Slack notifications on the IDunion project Slack workspace channel 'docker_indy-node'. The workflow is doing a weekly trivy scan and filters all high and critical CVEs and publishes them to the mentioned Slack channel. For that to work a secret webhook URL needs to be included in this repo. The name of the secret needs to be

SLACK_WEBHOOK_URL_IDU

corresponding to the name in the file. The webhook URL needs to be a secret otherwise it will be disabled.

Best regards Sebastian