Description of the feature request
Context: Slack
The trigger map should allow branch exclusion, e.g. !branch_name to trigger a certain workflow for all branches except branch_name.
Use case / for what or how I would use it
We have a branch called l10n_develop where translations are synced back from the localization service once translators update a string. The service creates a new commit for each language, creates a pull request, and then pushes a new commit for subsequent changes (see New Crowdin translations by iotasyncbot · Pull Request #1222 · iotaledger/trinity-wallet · GitHub for an example). This can result in a lot of builds being created even though we don’t need our tests to run on these changes.