jest: [Bug]: config options set at root level aren't copied to `projects`

Version

29.5.0

Steps to reproduce

1. Clone minimal repo: https://gist.github.com/davidjb/eb8803286d8e6b1f0ca0d95e231fe3ca
2. npm i
3. Mock project dir: mkdir -p path/to/example
4. npm test -- --showConfig
5. Observe config output where child project configuration has Jest’s defaults set and not the root-level config for testMatch, testPathIgnorePatterns, watchPathIgnorePatterns and so on (output below).

Expected behavior

The documentation for projects (https://jestjs.io/docs/configuration#projects-arraystring--projectconfig) states that:

With the projects option enabled, Jest will copy the root-level configuration options to each individual child configuration during the test run, resolving its values in the child’s context.

So, the expectation is that an option set at the global level would be applied to all project entries.

Actual behavior

Project config use Jest’s configuration defaults instead of the root-level config set. Interestingly, the global options don’t actually show up under globalConfig, either:

{
  "configs": [
    {
      [...]
      "testMatch": [
        "**/__tests__/**/*.[jt]s?(x)",
        "**/?(*.)+(spec|test).[tj]s?(x)"
      ],
      "testPathIgnorePatterns": [
        "/node_modules/"
      ],
      [...]
      "watchPathIgnorePatterns": []
    }
  ],
  "globalConfig": {
    [...]
    "projects": [
      {
        "displayName": "example",
        "rootDir": "path/to/example"
      }
    ],
    [...]
    "testTimeout": 12345,
    [...]
  },
  "version": "29.5.0"
}

Additional context

Note that this was tested in both package.json and jest.config.js - the results are the same. Also, whilst this example focuses on testMatch, testPathIgnorePatterns and watchPathIgnorePatterns, the issue appears to affect all options I’ve tried - such as setupFilesAfterEnv too.

That said, some options (such as testTimeout) will automatically apply to all projects, presumably because they’re set at a global level and can’t be applied to a project. In this specific case trying to set testTimeout for a project results in a Validation Warning: Unknown option "testTimeout" with value 678 was found. This is probably a typing mistake. Fixing it will remove this message.

Environment

System:
    OS: macOS 13.4
    CPU: (8) arm64 Apple M1 Pro
  Binaries:
    Node: 20.2.0 - /opt/homebrew/bin/node
    Yarn: 3.4.1 - /opt/homebrew/bin/yarn
    npm: 9.6.6 - /opt/homebrew/bin/npm
  npmPackages:
    jest: ^29.5.0 => 29.5.0