zig: make throwPretty use JSError

[nektro]

progress towards #15141

[robobun]

❌ @nektro, your commit 3bc8942 has 18 failures in #6872:

test/regression/issue/09041.test.ts - 1 failing on 🐧 3.20 x64

test/js/bun/http/bun-serve-static.test.ts - timeout on 🐧 3.20 x64-baseline

test/js/node/test/parallel/worker-nested-uncaught.test.js - segmentation fault on 🐧 3.20 aarch64

test/js/node/test/parallel/worker-nested-uncaught.test.js - segmentation fault on 🐧 3.20 x64

test/js/node/test/parallel/worker-nested-uncaught.test.js - segmentation fault on 🐧 3.20 x64-baseline

test/integration/next-pages/test/dev-server.test.ts - 1 failing on 🐧 3.20 x64

test/integration/next-pages/test/dev-server.test.ts - 1 failing on 🐧 3.20 x64-baseline

test/js/node/child_process/child_process.test.ts - 1 failing on 🐧 3.20 aarch64

test/js/node/child_process/child_process.test.ts - 1 failing on 🐧 3.20 x64-baseline

test/js/node/child_process/child_process.test.ts - 1 failing on 🐧 3.20 x64

test/js/web/timers/setTimeout.test.js - 1 failing on 🐧 22.04 aarch64

test/js/node/test/parallel/fs-watch-recursive-linux-parallel-remove.test.js - 1 failing on 🐧 20.04 x64-baseline

test/js/node/test/parallel/fs-watch-recursive-linux-parallel-remove.test.js - 1 failing on 🐧 22.04 x64-baseline

test/js/node/test/parallel/fs-watch-recursive-linux-parallel-remove.test.js - 1 failing on 🐧 12 x64

test/js/node/test/parallel/fs-watch-recursive-linux-parallel-remove.test.js - 1 failing on 🐧 22.04 x64

test/js/node/test/parallel/fs-watch-recursive-linux-parallel-remove.test.js - 1 failing on 🐧 3.20 aarch64

test/js/node/test/parallel/fs-watch-recursive-linux-parallel-remove.test.js - 1 failing on 🐧 3.20 x64

test/js/node/test/parallel/fs-watch-recursive-linux-parallel-remove.test.js - 1 failing on 🐧 3.20 x64-baseline

test/js/web/fetch/fetch.test.ts - 1 failing on 🍎 14 aarch64

test/v8/v8.test.ts - 24 failing on 🐧 20.04 aarch64

test/v8/v8.test.ts - 22 failing on 🐧 3.20 aarch64

test/v8/v8.test.ts - 22 failing on 🐧 3.20 x64

test/v8/v8.test.ts - 22 failing on 🐧 3.20 x64-baseline

test/integration/next-pages/test/next-build.test.ts - 1 failing on 🐧 22.04 aarch64

test/integration/next-pages/test/next-build.test.ts - 1 failing on 🐧 12 x64

test/integration/next-pages/test/next-build.test.ts - 1 failing on 🐧 22.04 x64

test/js/node/watch/fs.watch.test.ts - 3 failing on 🍎 14 aarch64

test/js/node/test/parallel/fs-watch.test.js - 1 failing on 🍎 14 aarch64

test/js/node/test/parallel/fs-watch-recursive-add-file-to-existing-subfolder.test.js - 1 failing on 🍎 14 aarch64

test/js/node/test/parallel/fs-watch-encoding.test.js - 2 failing on 🍎 14 aarch64

test/js/web/fetch/fetch.tls.test.ts - 1 failing on 🍎 13 aarch64

test/js/bun/http/serve.test.ts - 1 failing on 🍎 13 aarch64

test/js/bun/http/serve.test.ts - segmentation fault on 🐧 3.20 aarch64

test/js/bun/http/serve.test.ts - 1 failing on 🍎 14 x64

test/js/bun/http/serve.test.ts - 1 failing on 🍎 13 x64

test/js/bun/http/serve.test.ts - segmentation fault on 🐧 3.20 x64

test/js/bun/http/serve.test.ts - segmentation fault on 🐧 3.20 x64-baseline

test/cli/hot/hot.test.ts - timeout on 🪟 2019 x64-baseline

test/cli/hot/hot.test.ts - timeout on 🐧 3.20 x64

test/cli/run/require-cache.test.ts - 1 failing on 🪟 2019 x64