Add Dependabot auto-merge workflow#229

Marenz merged 2 commits intofrequenz-floss:v0.x.xfrequenz-floss/frequenz-client-dispatch-python:v0.x.xfrom

Marenz:add-dependabot-workflowMarenz/frequenz-client-dispatch-python:add-dependabot-workflowCopy head branch name to clipboard