fix: disable code-splitting to workaround an issue in deno 2.x's deno cache functionality

[JakeChampion]

currently this package is published in this structure:

dist/
├── bootstrap
│   ├── main.cjs
│   ├── main.d.cts
│   ├── main.d.ts
│   └── main.js
├── cache-854474ad.d.ts
├── chunk-DZNRKSSF.js
├── main.cjs
├── main.d.cts
├── main.d.ts
└── main.js

if we try to cache this package using deno, right now it will end up with a file structure like this:

vendor
├── cdn.jsdelivr.net
│   └── npm
│       └── @netlify
│           └── [email protected]
│               └── dist
│                   ├── #chunk-i5fzdz6v_a8179.js
│                   └── bootstrap
│                       └── main.js

this is incorrect because ./dist/bootstrap/main.js wants to import from "../chunk-I5FZDZ6V.js" but that file does not exist, deno has named the file #chunk-i5fzdz6v_a8179.js

we can work around this issue by ensuring we do not code split the files, so that our published package becomes this:

dist/
├── bootstrap
│   ├── main.cjs
│   ├── main.d.cts
│   ├── main.d.ts
│   └── main.js
├── cache-854474ad.d.ts
├── main.cjs
├── main.d.cts
├── main.d.ts
└── main.js