LU-16515 tests: disable sanity test_118c/118d

LU-16515 tests: disable sanity test_118c/118d

Temporarily disable sanity test_118c and test_118d until there is
a fix available, since this is failing a large fraction of tests.

Lustre-change: https://review.whamcloud.com/50470
Lustre-commit: 7c52cbf65218d77c0594f92981173aa7d78f6758

Test-Parameters: trivial
Signed-off-by: Andreas Dilger <adilger@whamcloud.com>
Change-Id: I16ebbc470a126bb99b5c3ecdf93407d6b73ebbe5
Reviewed-by: Yang Sheng <ys@whamcloud.com>
Reviewed-on: https://review.whamcloud.com/c/ex/lustre-release/+/50794
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>