LU-18027 tests: skip sanity/56ei in interop testing

LU-18027 tests: skip sanity/56ei in interop testing

sanity test_56ei is checking for projid on special files, but this
is not working with older servers.  Skip it in this case.

Test-Parameters: trivial testlist=sanity env=ONLY=56ei serverversion=2.14
Fixes: 501e5b2c8a ("LU-18027 lfs: lfs find handling special files")
Signed-off-by: Andreas Dilger <adilger@whamcloud.com>
Change-Id: Id20b2677d84e7f3504f410262ead6e8c7e83af62
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/56265
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Shaun Tancheff <shaun.tancheff@hpe.com>
Reviewed-by: Caleb Carlson <caleb.carlson@hpe.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>