fix(burn-in): use hashtable splat for conditional -SkipArtifact in Start-BurnInTest

In PS 5.1, $(if (...) { '-SkipArtifact' }) inside a call produces the
literal string '-SkipArtifact' bound as a positional argument (-> IPList),
not interpreted as a switch name.
Fixed by building a hashtable and setting SkipArtifact = \True when needed.

scripts/Start-BurnInTest.ps1

@@ -58,21 +58,24 @@ $ErrorActionPreference = 'Stop'
 
 $scriptDir = Split-Path -Parent $MyInvocation.MyCommand.Path
 
-& "$scriptDir\Test-CapacityBurnIn.ps1" `
-    -RepoUrl               'http://10.10.20.11:3100/ci/burnin-dummy.git' `
-    -Branch                'main' `
-    -TemplatePath          'F:\CI\Templates\WinBuild2025\WinBuild2025.vmx' `
-    -SnapshotName          'BaseClean' `
-    -CloneBaseDir          'F:\CI\BuildVMs' `
-    -ArtifactBaseDir       'F:\CI\Artifacts' `
-    -GuestCredentialTarget 'BuildVMGuest' `
-    -GiteaCredentialTarget 'GiteaPAT' `
-    -VmrunPath             'C:\Program Files (x86)\VMware\VMware Workstation\vmrun.exe' `
-    -GuestOS               'Auto' `
-    -BuildCommand          $BuildCommand `
-    -Parallelism           $Parallelism `
-    -Rounds                $Rounds `
-    -RoundTimeoutMinutes   $RoundTimeoutMinutes `
-    $(if (-not $NoSkipArtifact) { '-SkipArtifact' })
+$burnInParams = @{
+    RepoUrl               = 'http://10.10.20.11:3100/ci/burnin-dummy.git'
+    Branch                = 'main'
+    TemplatePath          = 'F:\CI\Templates\WinBuild2025\WinBuild2025.vmx'
+    SnapshotName          = 'BaseClean'
+    CloneBaseDir          = 'F:\CI\BuildVMs'
+    ArtifactBaseDir       = 'F:\CI\Artifacts'
+    GuestCredentialTarget = 'BuildVMGuest'
+    GiteaCredentialTarget = 'GiteaPAT'
+    VmrunPath             = 'C:\Program Files (x86)\VMware\VMware Workstation\vmrun.exe'
+    GuestOS               = 'Auto'
+    BuildCommand          = $BuildCommand
+    Parallelism           = $Parallelism
+    Rounds                = $Rounds
+    RoundTimeoutMinutes   = $RoundTimeoutMinutes
+}
+if (-not $NoSkipArtifact) { $burnInParams['SkipArtifact'] = $true }
+
+& "$scriptDir\Test-CapacityBurnIn.ps1" @burnInParams
 
 exit $LASTEXITCODE