Remove exp legacy-tempest-dsvm-full-devstack-plugin-nfs

It is a legacy experimental job on a EM branch.

See also the changset
Ifd4387a02b3103e1258e146e63c73be1ad10030c

Change-Id: Ib4f1cfe12bbd1172dcf2b413332f9a1e7fb0d1b0

.zuul.yaml

@@ -542,21 +542,6 @@
               - ^nova/locale/.*$
               - ^nova/tests/.*$
               - ^tests-py3.txt$
-        - legacy-tempest-dsvm-full-devstack-plugin-nfs:
-            irrelevant-files:
-              - ^(placement-)?api-.*$
-              - ^(test-|)requirements.txt$
-              - ^.*\.rst$
-              - ^.git.*$
-              - ^doc/.*$
-              - ^nova/hacking/.*$
-              - ^nova/locale/.*$
-              - ^nova/tests/.*$
-              - ^releasenotes/.*$
-              - ^setup.cfg$
-              - ^tests-py3.txt$
-              - ^tools/.*$
-              - ^tox.ini$
         - legacy-barbican-simple-crypto-dsvm-tempest-nova
         - devstack-plugin-ceph-tempest-py3:
             irrelevant-files: