LU-18042 tests: skip old server test for sanity-flr/0k

LU-18042 tests: skip old server test for sanity-flr/0k

Mirror extend a non-mirrored file in a directory with default
FLR layout needs server support, so this patch adds server version
checking to skip unsupported servers for sanity-flr/0k.

Test-Parameters: trivial
Fixes: 8005a374ca ("LU-15486 lod: mirroring plain file in mirrored-layout dir")
Signed-off-by: Bobi Jam <bobijam@whamcloud.com>
Change-Id: Id5ea10d654af3927c5aaffab17f15990694e9ed3
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/55996
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>
Reviewed-by: Li Xi <lixi@ddn.com>
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>