feat: support import.defer() for context module

[ahabhgk]

Summary

support import.defer() for context module:

const file = Math.random() > 0.5 ? "a.js" : "b.js";
import.defer("./dir/" + file);

What kind of change does this PR introduce?

feature

Did you add tests for your changes?

Yes

Does this PR introduce a breaking change?

No

If relevant, what needs to be documented once your changes are merged or what have you already documented?

With #20064 now webpack has full support for import.defer(), we can document that

[changeset-bot]

🦋 Changeset detected

Latest commit: bed44fa

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

This PR includes changesets to release 1 package

Name	Type
webpack	Minor

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[codspeed-hq]

Merging this PR will not alter performance

✅ 72 untouched benchmarks

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_{Comparing ahabhgk:dynamic-import-defer-context (bed44fa) with main (5ecc58d)}

[github-actions]

This PR is packaged and the instant preview is available (7b3b0f7).

Install it locally:

• npm

npm i -D webpack@https://pkg.pr.new/webpack@7b3b0f7

• yarn

yarn add -D webpack@https://pkg.pr.new/webpack@7b3b0f7

• pnpm

pnpm add -D webpack@https://pkg.pr.new/webpack@7b3b0f7