The current system python in the docker baseimage is py3.9, while the targetpython and hostpython built by p4a are py3.8, and this was causing linker issues in the pyqt5 build. It is also cleaner IMHO to have p4a handle what is needed for a recipe instead of assuming it is available in the system. (and I think this is how other existing recipes work) fixes https://github.com/spesmilo/electrum/issues/8016
python-for-android local recipes
These folders are recipes (build scripts) for most of our direct and transitive dependencies for the Android app. python-for-android has recipes built-in for many packages but it also allows users to specify their "local" recipes. Local recipes have precedence over the built-in recipes.
The local recipes we have here are mostly just used to pin down specific versions and hashes for reproducibility. The hashes are updated manually.