feat: ujson #1418

Job	Run time
build (1.20.x, GOARCH=amd64 GOOS=linux, gno)	47s
test (1.20.x, _test.cmd)	1m 54s
build (1.20.x, GOARCH=wasm GOOS=js, gno)	34s
test (1.20.x, _test.pkg)	1m 48s
build (1.21.x, GOARCH=amd64 GOOS=linux, gno)	47s
test (1.20.x, _test.gnolang.native)	1m 21s
build (1.21.x, GOARCH=wasm GOOS=js, gno)	49s
test (1.20.x, _test.gnolang.stdlibs)	1m 37s
test (1.20.x, _test.gnolang.realm)	1m 1s
test (1.20.x, _test.gnolang.pkg0)	3m 0s
test (1.20.x, _test.gnolang.pkg1)	8m 2s
test (1.20.x, _test.gnolang.pkg2)	7m 18s
test (1.20.x, _test.gnolang.other)	1m 8s
test (1.21.x, _test.cmd)	1m 30s
test (1.21.x, _test.pkg)	1m 36s
test (1.21.x, _test.gnolang.native)	1m 12s
test (1.21.x, _test.gnolang.stdlibs)	2m 4s
test (1.21.x, _test.gnolang.realm)	1m 18s
test (1.21.x, _test.gnolang.pkg0)	2m 29s
test (1.21.x, _test.gnolang.pkg1)	8m 42s
test (1.21.x, _test.gnolang.pkg2)	5m 53s
test (1.21.x, _test.gnolang.other)	1m 3s
	55m 53s

Provide feedback