allow cloudflare-specific js module

[edevil]

Mark cloudflare-specific js module as external so that scripts can be published that reference it.

What this PR solves / how to test:

import { EmailMessage } from "cloudflare:email";

Author has included the following, where applicable:

• Tests
• Changeset (Changeset guidelines)

Reviewer has performed the following, where applicable:

• Checked for inclusion of relevant tests
• Checked for inclusion of a relevant changeset
• [ ] Checked for creation of associated docs updates : no documentation needed for this just yet. I assume when the first official cloudflare:.. prefixed modules are announced there will be docs associated with it.
• Manually pulled down the changes and spot-tested

[changeset-bot]

🦋 Changeset detected

Latest commit: ec3c8ef

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

This PR includes changesets to release 1 package

Name	Type
wrangler	Minor

Not sure what this means? Click here to learn what changesets are.

Click here if you're a maintainer who wants to add another changeset to this PR

[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/4436097268/npm-package-wrangler-2905

You can reference the automatically updated head of this PR with:

npm install --save-dev https://prerelease-registry.devprod.cloudflare.dev/workers-sdk/prs/2905/npm-package-wrangler-2905

Or you can use npx with this latest build directly:

npx https://prerelease-registry.devprod.cloudflare.dev/workers-sdk/runs/4436097268/npm-package-wrangler-2905 dev path/to/script.js

Additional artifacts:

npm install https://prerelease-registry.devprod.cloudflare.dev/workers-sdk/runs/4436097268/npm-package-cloudflare-pages-shared-2905

Note that these links will no longer work once the GitHub Actions artifact expires.

[codecov]

Codecov Report

Merging #2905 (ec3c8ef) into main (9996ac4) will increase coverage by 0.03%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##             main    #2905      +/-   ##
==========================================
+ Coverage   73.94%   73.98%   +0.03%     
==========================================
  Files         167      167              
  Lines       10295    10299       +4     
  Branches     2748     2748              
==========================================
+ Hits         7613     7620       +7     
+ Misses       2682     2679       -3     

Impacted Files	Coverage Δ
packages/wrangler/src/bundle.ts	93.11% <100.00%> (+0.12%)	⬆️

... and 2 files with indirect coverage changes

[petebacondarwin]

Thanks for getting the ball rolling on this. We will also need to add a changeset and a test or two.

[edevil]

The test here would be if I could publish (or build) a script that tried to import this module. Is there an existing test suite that this could fit into?

[edevil]

Added test and changeset.

[petebacondarwin]

Great! Thanks for the quick turnaround @edevil - just a suggestion for the changeset description. Otherwise LGTM.