selinux-testsuite: Bump to latest upstream commit
    
    The main highlight is that filesystems tests are now run for all
    supported filesystems, instead of just the one that is native to the
    platform.
    
    Also, the testsuite no longer (directly) requires Python, so drop the
    dependency and a related workaround.
    
    Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>