Run jobs if requirements change

The dsvm jobs were not being run if only test-requirements.txt was
modified. However, devstack installs test-requirements so we should
run those jobs if that file changes.

The grenade multinode jobs were not being run if requirements.txt
was modified -- this was due to an extra '|' which caused it to be
considered an irrelevant file :-(

Change-Id: I1a49915ca52a93e77849dc5ead655656ad1bb34e

zuul.d/legacy-ironic-jobs.yaml

@@ -2,7 +2,7 @@
     name: legacy-ironic-dsvm-base
     parent: legacy-dsvm-base
     irrelevant-files:
-      - ^(test-|driver-)requirements.txt$
+      - ^driver-requirements.txt$
       - ^.*\.rst$
       - ^api-ref/.*$
       - ^doc/.*$
@@ -29,7 +29,7 @@
     name: legacy-ironic-dsvm-base-multinode
     parent: legacy-dsvm-base-multinode
     irrelevant-files:
-      - ^(test-|driver-|)requirements.txt$
+      - ^driver-requirements.txt$
       - ^.*\.rst$
       - ^api-ref/.*$
       - ^doc/.*$