cad17c4 tests: Fix failing ClearPartTestCase with latest blivet (#test)

1 file Authored by vtrefny 2 years ago, Committed by jkonecny 2 years ago,
    tests: Fix failing ClearPartTestCase with latest blivet (#test)
    
    Blivet now uses parted_partition.number for sorting partitions so
    we need to set it for the Mock in test_should_clear.
    
    See also https://github.com/storaged-project/blivet/pull/960
    
    (cherry picked from commit 5bbdd202ae092f8ddd50eda726b3b9f61465e21c)