Should-BeHashtable -Actual is at Position 1, should be Position 0 #2942

Should-BeHashtable is a single-subject assertion (only $Actual is positional, everything else is named), but $Actual is declared at Position = 1 instead of Position = 0. That is the same inconsistency #2933 fixed for Should-BeTrue/Should-BeNull etc., but Should-BeHashtable was not part of that sweep.

# src/functions/assert/Hashtable/Should-BeHashtable.ps1
[Parameter(Position = 1, ValueFromPipeline = $true)]
$Actual,

Should be Position = 0. Caught by the new assertion convention tests (#2941), which currently allow-list it. Once fixed, the allow-list entry should be removed.