fix: Files being included on wrong plats & ps3 postbuild

Minecraft.Client/Common/Buildsteps/PS3-postbuild.ps1

@@ -59,7 +59,7 @@ $fileCopies = @(
 )
 
 foreach ($copy in $fileCopies) {
-    $src = Join-Path $ProjectDir $copy.Source
+    $src = $copy.Source
     $dst = Join-Path $OutDir $copy.Dest
     if (Test-Path $src) {
         Copy-Item -Path $src -Destination $dst -Force