misc: convert @cypress/webpack-dev-server tests to vitest. Additionally, uses tsx to import ESM only packages into @cypress/webpack-dev-server

[AtofStryker]

• Closes N/A

Additional details

Converts @cypress/webpack-dev-server tests to vitest. Additionally, the package now uses tsx to import ESM only packages into @cypress/webpack-dev-server, which is a CommonJS module. This is because the dynamic import code does not work properly within the vitest context. This change shouldn't be disruptive

Steps to test

How has the user experience changed?

PR Tasks

• Have tests been added/updated?
• Has a PR for user-facing changes been opened in cypress-documentation?
• Have API changes been updated in the type definitions?

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Note

Migrates @cypress/webpack-dev-server tests from Mocha/Chai/Sinon to Vitest and replaces dynamic import logic with tsx-based ESM imports (e.g., find-up, Angular CLI modules).

• npm/webpack-dev-server
  • Testing: Migrate all tests to vitest; convert assertions/mocks; add vitest.config.ts; update scripts (test, test-debug).
  • ESM Imports: Remove src/dynamic-import.ts; use tsx/esm/api (tsImport) to load ESM-only modules like find-up and Angular CLI files; update angularHandler.ts and makeWebpackConfig.ts accordingly.
  • Tests/Fixtures: Update snapshots to Vitest format; adjust test utilities and timing; replace deprecated Mocha configs/support files.
  • Dependencies: Add vitest and tsx; drop Mocha/Chai/Sinon-related deps.
• Docs
  • Update guides/esm-migration.md to mark npm/webpack-dev-server as completed in Phase 2.

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[cypress]

cypress    Run #67132

Run Properties:   Passed #67132  •  404408e59d: chore: convert webpack-dev-server tests to vitest

Project	cypress
Branch Review	chore/webpack-dev-server-vitest
Run status	Passed #67132
Run duration	10m 50s
Commit	404408e59d: chore: convert webpack-dev-server tests to vitest
Committer	Bill Glesias
View all properties for this run ↗︎

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Test results
Failures	0
Flaky	0
Pending	1
Skipped	0
Passing	703
View all changes introduced in this branch ↗︎

UI Coverage  38.03%
Untested elements	132
Tested elements	81

Accessibility  97.39%
Failed rules	3 critical   7 serious   1 moderate   1 minor
Failed elements	62