feat: add --exclude CLI flag

[Namchee]

Description

This pull request adds a new flag --exclude as a CLI option that allows users to specify extra glob patterns to be ignored from tests. By default, it will merge the globs with existing default excludes.

Closes #4148

Please don't delete this checklist! Before submitting the PR, please make sure you do the following:

• It's really useful if your PR references an issue where it is discussed ahead of time. If the feature is substantial or introduces breaking changes without a discussion, PR might be closed.
• Ideally, include a test that fails without this PR but passes with it.
• Please, don't make changes to pnpm-lock.yaml unless you introduce a new test example.

Tests

• Run the tests with pnpm test:ci.

Documentation

• If you introduce new functionality, document it. You can run documentation with pnpm run docs command.

Changesets

• Changes in changelog are generated from PR name. Please, make sure that it explains your changes in an understandable manner. Please, prefix changeset messages with feat:, fix:, perf:, docs:, or chore:.

[netlify]

✅ Deploy Preview for fastidious-cascaron-4ded94 canceled.

Name	Link
🔨 Latest commit	f6da69f
🔍 Latest deploy log	https://app.netlify.com/sites/fastidious-cascaron-4ded94/deploys/65819a7a84444f00080cd70e

[sheremet-va]

It would also be nice if you can provide a test case for this feature. I don't think we have tests specifically for CLI commands, but you can create one.

[Namchee]

Good idea, will create a test for CLIs later.

[Namchee]

@sheremet-va , I think I have difficulties creating the CLI test since I don't know how to access the config from the running vitest instance. Do you have a pointer regarding this?

Alternatively, we can just provide test for resolveConfig since the merging logic happens there.

[sheremet-va]

I think I have difficulties creating the CLI test since I don't know how to access the config from the running vitest instance. Do you have a pointer regarding this?

You can see an example of a CLI test in #4399