Update dependency architect to v6.15.0 (#391)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

.circleci/config.yml

@@ -1,7 +1,7 @@
 version: 2.1
 
 orbs:
-  architect: giantswarm/architect@6.14.1
+  architect: giantswarm/architect@6.15.0
 
 workflows:
   test: