Revert "Exclude __pycache__ files from flatpak build"
    
    This reverts commit e1b9941462b82f208b814fc2f6e7f369bcda11a0, the underlying
    issue is reportedly fixed for f33 and those files are now generated by a Flatpak
    build after all:
    
    > Checking for unpackaged file(s): /usr/lib/rpm/check-files /builddir/build/BUILDROOT/libvoikko-4.1.1-8.module+f33+2+22783585.x86_64
    > error: Installed (but unpackaged) file(s) found:
    >    /app/lib/python3.9/site-packages/__pycache__/libvoikko.cpython-39.opt-1.pyc
    >    /app/lib/python3.9/site-packages/__pycache__/libvoikko.cpython-39.pyc
    >     Installed (but unpackaged) file(s) found:
    >    /app/lib/python3.9/site-packages/__pycache__/libvoikko.cpython-39.opt-1.pyc
    >    /app/lib/python3.9/site-packages/__pycache__/libvoikko.cpython-39.pyc