Fix PowerShell syntax error in prepare-machine.ps1 babeltrace2 installation

Co-authored-by: nibanks <[email protected]>

Author: Copilot

scripts/prepare-machine.ps1

@@ -538,7 +538,9 @@ if ($IsLinux) {
         sudo apt-get install -y build-essential
         sudo apt-get install -y liblttng-ust-dev
         # Try to install babeltrace2 first, then fallback to babeltrace
-        if (!sudo apt-get install -y babeltrace2 2>/dev/null) {
+        try {
+            sudo apt-get install -y babeltrace2 2>&1 | Out-Null
+        } catch {
             sudo apt-get install -y babeltrace
         }
         sudo apt-get install -y libssl-dev