breaking: remove support for create react app for component testing as it is no longer maintained

Closes #30028

Additional details

Create React App is de-facto abandoned and unsupported. Because of this, Cypress has chosen to remove CRA support for Component Testing in Cypress 14. This means that create-react-app users will need to use either webpack or vite to bundler their component tests. webpack support is supported with create-react-app if a user choses to eject their app.

[x] What happens when using prepublished binary against scaffolded CRA project? Can I eject?

If starting cypress without doing any migration, this error will throw in the cypress config

However, users can migrate via npm run eject with create-react-app, which will generate a webpack config. If users change their config from:

const { defineConfig } = require('cypress')

module.exports = defineConfig({
  component: {
    devServer: {
      framework: 'create-react-app',
      bundler: 'webpack',
    },
  },
})

process.env.NODE_ENV = 'development'
const { defineConfig } = require('cypress')
const webpackConfig = require('./config/webpack.config.js')

module.exports = defineConfig({
  component: {
    devServer: {
      framework: 'react',
      bundler: 'webpack',
      webpackConfig: webpackConfig('development'),
    },
  },
})

this does work

[x] Does scaffolding work with new projects?

It does work with new projects as react is selected and webpack is detected. However, a user will need to eject the application and point to the webpack config as shown above. Otherwise, the config will throw an error which is expected

[x] Provide options in the migration guide

Steps to test

Testing against prepublished binary to verify migration steps work as expected

How has the user experience changed?

PR Tasks

[x] Have tests been added/updated?
[x] Has a PR for user-facing changes been opened in cypress-documentation? https://github.com/cypress-io/cypress-documentation/pull/5987
[x] Have API changes been updated in the type definitions?

cypress Run #58281

Run Properties: Passed #58281 • b4aeb278b2: breaking: remove support for create react app for component testing as it is no ...

Project	`cypress`
Branch Review	`breaking/remove_create_react_app`
Run status	`Passed #58281`
Run duration	`09m 59s`
Commit	`b4aeb278b2: breaking: remove support for create react app for component testing as it is no ...`
Committer	`AtofStryker`
View all properties for this run ↗︎

Test results
Failures	`0`
Flaky	`0`
Pending	`1`
Skipped	`0`
Passing	`667`
View all changes introduced in this branch ↗︎

UI Coverage `38.03%`
Untested elements	`132`
Tested elements	`81`

Accessibility `92.06%`
Failed rules	`3 critical` `7 serious` `1 moderate` `1 minor`
Failed elements	`540`

cypress-io / cypress