Run the local pipeline whenever the parent pipeline triggers it

By default pipelines do not run in Merge Request context, but that's exactly what the parent ci-package-builder pipeline is now doing.

Add a rule to run the local pipeline in whatever context the parent pipeline triggered it.

debian/changelog

+apertis-dev-tools (0.2021.3) apertis; urgency=medium
+
+  * Run the local pipeline whenever the parent pipeline triggers it
+
+ -- Emanuele Aina <emanuele.aina@collabora.com>  Sun, 03 Oct 2021 19:29:07 +0000
+
 apertis-dev-tools (0.2021.2) apertis; urgency=medium
 
   * Fix installability on v2022dev2. Demote dependency on ribchester to a