libxcb 1.16
    
    Update package to version 1.16.
    
    Since upstream commit 78c492deaa7a ("Build xz tarballs instead of
    bzip2"), .tar.xz is used instead of .tar.bz2, update `Source0`
    accordingly.
    
    Also, upgrade the `BuildRequires` version of xcb-proto to >= 1.16 as
    required by upstream commit 151933465283 ("configure.ac: Require
    xcb-proto >= 1.16.0").