Stop-PowerShell.ps1

using namespace System.Management.Automation

function Stop-PowerShell {
    param(
        [Parameter(Mandatory, ValueFromPipeline)]
        [System.Diagnostics.Process] $Process,

        [Parameter()]
        [ValidateRange(1, [int]::MaxValue)]
        [int] $TimeoutSeconds = 10)

    process {
        try {
            $pipe = [Runspaces.NamedPipeConnectionInfo]::new($Process.Id)
            $rs = [runspacefactory]::CreateRunspace($pipe)
            $rs.Open()
            $ps = [powershell]::Create($rs).AddScript({
                Get-Runspace |
                    Where-Object { $_ -ne [runspace]::DefaultRunspace } |
                    ForEach-Object CloseAsync
            })
            $null = $ps.InvokeAsync()
            if (-not $Process.WaitForExit([timespan]::FromSeconds($TimeoutSeconds))) {
                $PSCmdlet.WriteError([ErrorRecord]::new(
                    "Failed to stop PowerShell with Process Id '$($Process.Id)'.",
                    'StopFailed',
                    [ErrorCategory]::OperationTimeout,
                    $null))
            }
        }
        catch {
            $PSCmdlet.WriteError($_)
        }
        finally {
            ${ps}?.Dispose()
            ${rs}?.Dispose()
        }
    }
}