repo-install-test: run on all build slaves again

It was not possible to reproduce the weird rpm errors on
admin2-deb9build, which had lead to limiting the build slaves to
build2-deb9build-ansible. Enable building on all again.

Closes: OS#4567
Change-Id: I82ef1f0c581de8ee826adedd9ecde6b4adaa36ba

jobs/repo-install-test.yml

@@ -39,11 +39,6 @@
                 docker-playground.git branch
           default: 'master'
     axes:
-      - axis:
-          type: slave
-          name: label
-          # Force using "build2-deb9build-ansible": https://osmocom.org/issues/4563#note-10
-          values: !!python/tuple [build2-deb9build-ansible]
       - axis:
           type: user-defined
           name: feed