To aggregate by all possible labels use '...' as the sole label name.
This effectively disables aggregation entirely, passing through all
alerts as-is. This is unlikely to be what you want, unless you have
a very low alert volume or your upstream notification system performs
its own grouping. Example: group_by: [...]
Signed-off-by: Kyryl Sablin <kyryl.sablin@schibsted.com>