This extends the Python[3] shebang fixup to all packages. Only Python scripts in `/usr/bin` will be handled at the moment. Later it may make sense to also cover executables in `/bin`, though typically Python executables shouldn't be placed there. Previously the shebang handling was only done for python[3]-pip & python[3]-setuptools. Signed-off-by: Alexandru Ardelean <ardeleanalex@gmail.com>lilik-openwrt-22.03