LU-12016 tests: skip sanity/156 in interop

LU-12016 tests: skip sanity/156 in interop

Since LU-12071 was backported to b_es5_2 the version check on b_es6_0
is incorrect and this part of the test_156 should be skipped.

Test-Parameters: trivial testlist=sanity env=ONLY=156 serverversion=EXA5
Fixes: 3043c6f189 ("LU-12071 osd-ldiskfs: bypass pagecache if requested")
Signed-off-by: Andreas Dilger <adilger@whamcloud.com>
Change-Id: I3fd96578e36675655fb265d83ba3f661950ab112
Reviewed-on: https://review.whamcloud.com/c/ex/lustre-release/+/49246
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>