dev-lang/zig: drop "threads" and "test" USE flags for 9999

See commit f28480799d.
Signed-off-by: Eric Joldasov <bratishkaerik@getgoogleoff.me>
Closes: https://github.com/gentoo/gentoo/pull/28177
Signed-off-by: Sam James <sam@gentoo.org>

dev-lang/zig/zig-9999.ebuild

@@ -18,8 +18,6 @@ fi
 
 LICENSE="MIT"
 SLOT="0"
-IUSE="test +threads"
-RESTRICT="!test? ( test )"
 
 BUILD_DIR="${S}/build"
 
@@ -60,7 +58,6 @@ src_configure() {
 	local mycmakeargs=(
 		-DZIG_USE_CCACHE=OFF
 		-DZIG_SHARED_LLVM=ON
-		-DZIG_SINGLE_THREADED="$(usex !threads)"
 		-DCMAKE_PREFIX_PATH=$(get_llvm_prefix ${LLVM_MAX_SLOT})
 	)