perf: omit empty ignoreList property from source maps

[xiaoxiaojx]

Summary
perf: omit empty ignoreList property from source maps

What kind of change does this PR introduce?
perf

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?
Nothing

[changeset-bot]

🦋 Changeset detected

Latest commit: b3d27ca

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

This PR includes changesets to release 1 package

Name	Type
webpack	Patch

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]

This PR is packaged and the instant preview is available (edfaa0f).

Install it locally:

• npm

npm i -D webpack@https://pkg.pr.new/webpack@edfaa0f

• yarn

yarn add -D webpack@https://pkg.pr.new/webpack@edfaa0f

• pnpm

pnpm add -D webpack@https://pkg.pr.new/webpack@edfaa0f

[alexander-akait]

Let's add a test case where we generate source map and using toMatch() with default generated properties of source map to catch such regressions

[codspeed-hq]

Merging this PR will not alter performance

✅ 72 untouched benchmarks

---

_{Comparing ignoreList (b3d27ca) with main (9a3b428)}

[alexander-akait]

Thanks