[nova] Hyper-V CI broken on stable branches

Dear Hyper-V CI maintainers, We noticed upstream that the Hyper-V CI has been failing on the stable/stein and stable/rocky (and perhaps older branches too) since this tempest change merged to unskip test_stamp_pattern: https://review.opendev.org/615434 Here are links to sample failed CI runs: stable/stein: http://cloudbase-ci.com/nova/674828/1/tempest/subunit.html.gz stable/rocky: http://cloudbase-ci.com/nova/674916/1/tempest/subunit.html.gz It looks like all is well on the master branch (looks like test_stamp_pattern does not run on master). Just wanted to alert you about the failures and see if anyone is available to fix it or add test_stamp_pattern to a skip list for Hyper-V CI. Cheers, -melanie