fix: Use esbuild inject API

[GrygrFlzr]

Fixes #1733.

Purpose

This makes the adapters use esbuild's inject API:

This option allows you to automatically replace a global variable with an import from another file. This can be a useful tool for adapting code that you don't control to a new environment.

In particular, this guarantees:

• Execution order before all user/kit code in build output
• Properly polyfilled bindings for fetch etc

Tests

• Run the tests with pnpm test and lint the project with pnpm lint and pnpm check

Changesets

• If your PR makes a change that should be noted in one or more packages' changelogs, generate a changeset by running pnpx changeset and following the prompts

[changeset-bot]

🦋 Changeset detected

Latest commit: d860475

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 4 packages

Name	Type
@sveltejs/adapter-netlify	Patch
@sveltejs/adapter-node	Patch
@sveltejs/adapter-vercel	Patch
@sveltejs/kit	Patch

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[benmccann]

The hn.svelte.dev example is printing ~20 warnings now when I run npm run build:

../../packages/adapter-netlify/files/shims.js:1:9: warning: Import "fetch" will always be undefined because the file "../../packages/kit/dist/install-fetch.js" has no exports
1 │ export { fetch, Response, Request, Headers } from '@sveltejs/kit/install-fetch'; // eslint-disable-line import/no-unresolved
╵ ~~~~~