sanity-hsm test_255 was added to the Lustre test suites for LU-11653 with patch https://review.whamcloud.com/33649 . This test will fail for all Lustre servers with version less than 2.12.0. Thus, we need to add a version check for sanity-hsm test 255.

Similarly, sanity-hsm test 260c was modified by patch https://review.whamcloud.com/#/c/33478/ to take advantage of the change implemented in LU-11653 and, thus, test 260c should be skipped for servers less than 2.12.0.