@cloudflare/wrangler postinstall script does not exit


I have to force exit, and the binary is not linked.

And I modified the script
```js
#!/usr/bin/env node

const why = require('why-is-node-running')
const { install } = require("./binary");

install().then(() => {
setInterval(() => {
console.log('-------');
why()
}, 1000)
})
```

And logs as
```txt
$ node ./install-wrangler.js
Downloading release https://workers.cloudflare.com/get-npm-wrangler-binary/1.7.0/x86_64-apple-darwin
wrangler has been installed!
-------
There are 10 handle(s) keeping the process running

# TTYWRAP
/Users/magicdawn/.npm-global/lib/node_modules/@cloudflare/wrangler/node_modules/debug/src/node.js:76 - : tty.isatty(process.stderr.fd);
/Users/magicdawn/.npm-global/lib/node_modules/@cloudflare/wrangler/node_modules/debug/src/debug.js:120 - debug.useColors = exports.useColors();
/Users/magicdawn/.npm-global/lib/node_modules/@cloudflare/wrangler/node_modules/follow-redirects/index.js:6 - var debug = require("debug")("follow-redirects");

# SIGNALWRAP
/Users/magicdawn/.npm-global/lib/node_modules/@cloudflare/wrangler/node_modules/debug/src/node.js:76 - : tty.isatty(process.stderr.fd);
/Users/magicdawn/.npm-global/lib/node_modules/@cloudflare/wrangler/node_modules/debug/src/debug.js:120 - debug.useColors = exports.useColors();
/Users/magicdawn/.npm-global/lib/node_modules/@cloudflare/wrangler/node_modules/follow-redirects/index.js:6 - var debug = require("debug")("follow-redirects");

# TTYWRAP
/Users/magicdawn/.npm-global/lib/node_modules/@cloudflare/wrangler/node_modules/binary-install/src/binary.js:88 - console.log("Downloading release", this.url);
/Users/magicdawn/.npm-global/lib/node_modules/@cloudflare/wrangler/binary.js:37 - return binary.install();

# TCPWRAP
(unknown stack trace)

# TLSWRAP
(unknown stack trace)

# DNSCHANNEL
(unknown stack trace)

# HTTPCLIENTREQUEST
(unknown stack trace)

# Timeout
/Users/magicdawn/.npm-global/lib/node_modules/@cloudflare/wrangler/install-wrangler.js:7 - setInterval(() => {

# ZLIB
/Users/magicdawn/.npm-global/lib/node_modules/@cloudflare/wrangler/node_modules/minizlib/index.js:60 - this[_handle] = new realZlib[mode](opts)
/Users/magicdawn/.npm-global/lib/node_modules/@cloudflare/wrangler/node_modules/minizlib/index.js:193 - super(opts, mode)
/Users/magicdawn/.npm-global/lib/node_modules/@cloudflare/wrangler/node_modules/minizlib/index.js:292 - super(opts, 'Unzip')
/Users/magicdawn/.npm-global/lib/node_modules/@cloudflare/wrangler/node_modules/tar/lib/parse.js:347 - this[UNZIP] = new zlib.Unzip()

# TickObject
(unknown stack trace)
```

Start with install-wrangler.js and binary.js, then reproduce the npm installation described in the report. Check why the postinstall process remains active and why the binary is not linked. Done means the installation completes without requiring a forced exit and the binary is linked.

Written by the indexing model from the issue text.