chore: add DCO to release please

Signed-off-by: Todd Baert <todd.baert@dynatrace.com>

Author: toddbaert

.github/workflows/release.yml

@@ -25,6 +25,7 @@ jobs:
         with:
           token: ${{secrets.RELEASE_PLEASE_ACTION_TOKEN}}
           target-branch: main
+          signoff: "OpenFeature Bot <109696520+openfeaturebot@users.noreply.github.com>"
 
       # These steps are only run if this was a merged release-please PR
       - name: checkout