zig: always set a reasonable NOFILE rlimit max

[nektro]

progress towards #918

this should fix the musl segfault in test/js/bun/http/serve.test.ts

us_create_timer is allowed to return a null pointer and our code doesn't currently handle this
will send real fix in followup

additionally,

closes #15184

setting the ulimit manually should never be necessary but it appeared to be so because empirically the NOFILE rlimit was coming back as 1024/4096 on alpine and we were prematurely getting EMFILE in the course of normal operation

[robobun]

❌ @nektro, your commit 0753741 has 11 failures in #6394:

test/cli/install/registry/bun-install-registry.test.ts - timeout on 🐧 3.20 x64

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/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/cli/install/bun-run.test.ts - 1 failing on 🐧 3.20 x64

test/cli/install/bun-run.test.ts - 1 failing on 🐧 3.20 x64-baseline

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

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/js/bun/ffi/cc.test.ts - 1 failing on 🐧 3.20 aarch64

test/js/bun/ffi/cc.test.ts - 1 failing on 🐧 3.20 x64

test/js/bun/ffi/cc.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

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

test/cli/install/bun-link.test.ts - 4 failing on 🐧 3.20 aarch64

test/cli/install/bun-link.test.ts - 4 failing on 🐧 3.20 x64

test/cli/install/bun-link.test.ts - 4 failing on 🐧 3.20 x64-baseline

test/js/web/websocket/websocket-client.test.ts - 2 failing on 🪟 2019 x64

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

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