fix(reporter)!: remove deprecated APIs - #8223

Description

• Ref. feat: introduce the new reporter API #7069
• fix(reporter)!: remove onFinished
  • Simply using testModule.task everywhere. At first I started to convert all task usage to testModule, but it was too much work. Got BaseReporter quite far but error handling was complex now.
• fix(reporter)!: remove onPathsCollected
• fix(reporter)!: remove onSpecsCollected
• fix(reporter)!: remove onCollected
• fix(reporter)!: mark onTaskUpdate as @internal
  • Marking as internal instead of removing due to WebSocketReporter, UI and BenchmarkReporter usage

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:.