fix: render a helpful build error if a Service Worker mode Worker has imports

[petebacondarwin]

A common mistake is to forget to export from the entry-point of a Worker, which causes
Wrangler to infer that we are in "Service Worker" mode.

In this mode, imports to external modules are not allowed.
Currently this only fails at runtime, because our esbuild step converts these imports to an internal __require() call that throws an error.
The error message is misleading and does not help the user identify the cause of the problem.
This is particularly tricky where the external imports are added by a library or our own node.js polyfills.

Fixes #6648

What this PR solves / how to test

Fixes #[insert GH or internal issue number(s)].

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[changeset-bot]

🦋 Changeset detected

Latest commit: f3ce6ee

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

This PR includes changesets to release 2 packages

Name	Type
wrangler	Patch
@cloudflare/vitest-pool-workers	Patch

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[threepointone]

Are you sure we can't make it actually work? I think require()s work in the runtime.
If we make both modules/SW workers compile to esm, would that fix tthis?

workers-sdk/packages/wrangler/src/deployment-bundle/bundle.ts

Line 399 in dc9039a

format: entry.format === "modules" ? "esm" : "iife",

(Happy to be wrong)

[threepointone]

If esm is an issue, making that cjs might also do it

[threepointone]

For posterity, I was wrong, can't do imports/requires in a Service Worker

[github-actions]

A wrangler prerelease is available for testing. You can install this latest build in your project with:

npm install --save-dev https://prerelease-registry.devprod.cloudflare.dev/workers-sdk/runs/11130701217/npm-package-wrangler-6872

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npm install --save-dev https://prerelease-registry.devprod.cloudflare.dev/workers-sdk/prs/6872/npm-package-wrangler-6872

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npx https://prerelease-registry.devprod.cloudflare.dev/workers-sdk/runs/11130701217/npm-package-wrangler-6872 dev path/to/script.js

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npx https://prerelease-registry.devprod.cloudflare.dev/workers-sdk/runs/11130701217/npm-package-create-cloudflare-6872 --no-auto-update

npm install https://prerelease-registry.devprod.cloudflare.dev/workers-sdk/runs/11130701217/npm-package-cloudflare-kv-asset-handler-6872

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npm install https://prerelease-registry.devprod.cloudflare.dev/workers-sdk/runs/11130701217/npm-package-cloudflare-workers-editor-shared-6872

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---

[email protected] includes the following runtime dependencies:

Package	Constraint	Resolved
miniflare	workspace:*	3.20240925.0
workerd	1.20240925.0	1.20240925.0
workerd --version	1.20240925.0	2024-09-25

Please ensure constraints are pinned, and miniflare/workerd minor versions match.

[irvinebroque]

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