Stop using our own build of python3 for Windows/macOS/android builds
We are currently using our own build of python3 to build firefox for Windows and macOS.
We are also using our own build of python3 for Windows, macOS or Android builds in the following components:
- android-components
- application-services
- fenix
- geckoview
- glean
- https-everywhere
- ninja
After switching to bullseye (#40354 (closed)) we should check if we can avoid building our own python and use the one from bullseye.