3.9
bpo-31569: correct PCBuild/ case to PCbuild/ in build scripts and docs (GH-3711)
Closes #27314: Fixes launcher installer upgrade table.
Issue #27756: Adds new icons for Python files and processes on Windows. Designs by Cherry Wang.
Issue #27469: Adds a shell extension to the launcher so that drag and drop works correctly.
bpo-39631: Fix file association MIME type in the Windows installer (GH-20205)