cli/praefect: Quarantine tests in cli/praefect
Currently several tests in the cli/praefect package are known to be flaky. These include:
TestCheckSubcommand/positional_argumentsTestDatalossSubcommandTestAcceptDatalossSubcommandTestConfiguration_validate
This change uses testhelper.SkipQuarantinedTest to quarantine these
tests so it skips test execution until the flakiness is resolved.
Edited by Justin Tobler