Remove test that is not working from the weekly pipeline
Remove test that is not working from the weekly pipeline

This test: collections/memory/kv_fragmentation_5M_1s_1c.test has not
had a successful Jenkins build in a long time and every run takes 10
hours, only to be aborted. For example, a couple of past runs:
http://perf.jenkins.couchbase.com/job/ares/24992/
http://perf.jenkins.couchbase.com/job/ares/24829/
http://perf.jenkins.couchbase.com/job/ares/24686/

Change-Id: I5b0bde5f5b83f5e118db962623bbac14587a1155
Reviewed-on: https://review.couchbase.org/c/perfrunner/+/165735
Tested-by: Build Bot <80754af91bfb6d1073585b046fe0a474ce868509@couchbase.com>
Reviewed-by: vikas chaudhary <c251871a64d7d31888eace0406cb3d4c419d5f73@couchbase.com>

couchbase/perfrunner,couchbase/perfrunner,couchbase/perfrunner,couchbase/perfrunner,couchbase/perfrunner,couchbase/perfrunner