Fix Windows build: correct site-packages path in cleanup step

Co-authored-by: t0mdavid-m <57191390+t0mdavid-m@users.noreply.github.com>

Author: Copilot

.github/workflows/build-windows-executable-app.yaml

@@ -248,7 +248,7 @@ jobs:
     - name: Clean up unnecessary Python files
       shell: pwsh
       run: |
-        $sitePkgs = "py/Lib/site-packages"
+        $sitePkgs = "python-${{ env.PYTHON_VERSION }}/Lib/site-packages"
 
         # Remove __pycache__ directories
         Get-ChildItem -Path $sitePkgs -Recurse -Directory -Filter "__pycache__" | Remove-Item -Recurse -Force