Fix pin images task with atmosphere_image_prefix

This change also includes a skip for running jobs when any changes
in the `build` folder are done.

Change-Id: I632a2d71beb4227f9067ed936550a714df269232
diff --git a/zuul.d/container-images/base.yaml b/zuul.d/container-images/base.yaml
index 0be248f..5be0310 100644
--- a/zuul.d/container-images/base.yaml
+++ b/zuul.d/container-images/base.yaml
@@ -24,6 +24,7 @@
     name: atmosphere-buildset-registry
     parent: ci-buildset-registry
     irrelevant-files:
+      - ^build/
       - ^doc/
       - ^releasenotes/
 
@@ -32,6 +33,7 @@
     parent: ci-build-container-image
     abstract: true
     irrelevant-files:
+      - ^build/
       - ^doc/
       - ^releasenotes/
     vars: &image_vars
@@ -47,6 +49,7 @@
     name: atmosphere-promote-container-image
     parent: ci-promote-container-image
     irrelevant-files:
+      - ^build/
       - ^doc/
       - ^releasenotes/
     nodeset: