dlvsym() is used by the libepoxy test suite, but this is glibc-specific and
isn't present in musl.
Instead of adding an option to control whether dlvsym is available (which could
be detected by Meson), as we don't install the test suite simply add an option
to disable the entire test suite (and submit the patch upstream).
Also remove the build dependency on util-macros as that is a remnant of the
autotools build.
Signed-off-by: Ross Burton <ross.burton@intel.com>
