Update to 0.0.99.6
    
    Start using the golang-ipath(...) virtual Provides for BuildRequires
    because they use the top-level import paths and are closer to what is
    listed in the upstream go.mod.  The golang(...) virtual Provides mention
    each individual Go package within a Go module, and bigger modules can
    have several packages in them.  It is noisy and tedious to keep up with
    the list of packages that are currently in use, by looking at all the Go
    source files, and then to list them as BuildRequires.
    
    Update the compiler and linker flags for Fedora by incorporating some of
    the changes to the distribution's defaults up to Fedora 39, which is the
    oldest supported Fedora.  Switch to using the GO_BUILDTAGS and
    GO_LDFLAGS environment variables, because their unprefixed counterparts
    have been deprecated [1], and start annotating the toolbox(1) binary
    with an ELF note that identifies the RPM for which it was built [2].
    
    However, the change to use the RPM's %{name}, %{version}, %{release} and
    the SOURCE_DATE_EPOCH environment variable [3], instead of /dev/urandom,
    to generate the build ID annotation for the toolbox(1) binary [4] was
    left out.  It will need more work to propagate the RPM's %{name},
    %{version} and %{release} to Meson.
    
    Stop carrying the downstream patch for the compiler and linker flags for
    PPC64.  The architecture was already discontinued from Fedora 29 [5],
    even before the patch was added [6].  It was added purely for the sake
    of completeness, and in the last four years since it was introduced, it
    hasn't been tested or used.  At this point it's becoming too much of a
    maintenance burden, and removing it silences the %ifarch-applied-patch
    warning from rpmlint.
    
    Fill in some of the missing Requires for the toolbox-tests sub-package.
    
    [1] go-rpm-macros commit bc7e5cc55c4709e8
        https://pagure.io/go-rpm-macros/c/bc7e5cc55c4709e8
    
    [2] Fedora redhat-rpm-config commit 57edf0cad7b089ed
        https://src.fedoraproject.org/rpms/redhat-rpm-config/c/57edf0cad7b089ed
        https://fedoraproject.org/wiki/Changes/Package_information_on_ELF_objects
    
    [3] https://reproducible-builds.org/docs/source-date-epoch/
    
    [4] go-rpm-macros commit 1980932bf3a21890
        https://pagure.io/go-rpm-macros/c/1980932bf3a21890
        https://fedoraproject.org/wiki/Changes/ReproduciblePackageBuilds
    
    [5] https://fedoraproject.org/wiki/Changes/DiscontinuePPC64
    
    [6] Commit ba60453d216a9226
    
    https://src.fedoraproject.org/rpms/toolbox/pull-request/22