feat!(coverage): v8 to support only AST based remapping

[AriPerkkio]

Description

• Continues feat(coverage): v8 experimental AST-aware remapping #7736
• Closes Enable V8 coverage's experimentalAstAwareRemapping by default and remove old remapping mode #7928
• Fixes @vitest/coverage-v8 & [email protected]+ #8114
• Fixes Branch not covered for vue (or quasar) imports after 3.1.4 version #8131

Vitest's V8 code coverage provider is now using more accurate coverage result remapping logic.
It is expected for users to see changes in their coverage reports when updating from Vitest v3.

In the past Vitest used v8-to-istanbul for remapping V8 coverage results into your source files.
This method wasn't very accurate and provided plenty of false positives in the coverage reports.
We've now developed a new package that utilizes AST based analysis for the V8 coverage.
This allows V8 reports to be as accurate as @vitest/coverage-istanbul reports.

• Coverage ignore hints have updated. See Coverage | Ignoring Code.
• coverage.ignoreEmptyLines is removed. Lines without runtime code are no longer included in reports.
• coverage.experimentalAstAwareRemapping is removed. This option is now enabled by default, and is the only supported remapping method.
• coverage.ignoreClassMethods is now supported by V8 provider too.

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:.

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