React-Docgen: Make error-handling more gentle

[valentinpalkovic]

Closes #25053

What I did

Storybook 7.6, we have replaced the babel-plugin-react-docgen plugin with a custom Webpack5 loader, which works independently of the used compiler (SWC, Babel, ...). The loader throws an Error, though, as soon as a file cannot be processed.

An Error is not thrown anymore but instead log a warning to the user. In --loglevel=debug mode a stack trace should be available to report bug reports for react-docgen.

Checklist for Contributors

Testing

The changes in this PR are covered in the following automated tests:

• stories
• unit tests
• integration tests
• end-to-end tests

Manual testing

This section is mandatory for all contributions. If you believe no manual test is necessary, please state so explicitly. Thanks!

1. Clone https://github.com/zooniverse/front-end-monorepo
2. Checkout dependabot/npm_and_yarn/storybook/react-webpack5-7.6.1
3. yarn install (Node 20)
4. Go to packages/lib-classifier and run yarn install
5. yarn storybook -> it should fail
6. Precompile preset-react-webpack from the monorepo and swap out the files
7. A warning should be shown
8. Start Storybook with yarn storybook loglevel=debug -> Now a stacktrace is shown as well

Documentation

• Add or update documentation reflecting your changes
• If you are deprecating/removing a feature, make sure to update
  MIGRATION.MD

Checklist for Maintainers

• When this PR is ready for testing, make sure to add ci:normal, ci:merged or ci:daily GH label to it to run a specific set of sandboxes. The particular set of sandboxes can be found in code/lib/cli/src/sandbox-templates.ts

• Make sure this PR contains one of the labels below:

  Available labels

  • bug: Internal changes that fixes incorrect behavior.
  • maintenance: User-facing maintenance tasks.
  • dependencies: Upgrading (sometimes downgrading) dependencies.
  • build: Internal-facing build tooling & test updates. Will not show up in release changelog.
  • cleanup: Minor cleanup style change. Will not show up in release changelog.
  • documentation: Documentation only changes. Will not show up in release changelog.
  • feature request: Introducing a new feature.
  • BREAKING CHANGE: Changes that break compatibility in some way with current major version.
  • other: Changes that don't fit in the above categories.

🦋 Canary release

This PR does not have a canary release associated. You can request a canary release of this pull request by mentioning the @storybookjs/core team here.

core team members can create a canary release here or locally with gh workflow run --repo storybookjs/storybook canary-release-pr.yml --field pr=<PR_NUMBER>