Support Cypress 15 and Vite 4 (fix #410, fix #403, fix #401)

[FelixNumworks]

What kind of change does this PR introduce? (check at least one)

• Bugfix
• New test runner
• Documentation
• Feature
• Code style update
• Refactor
• Build-related changes
• Other, please describe:

If you are adding a new test runner, have you...? (check all)

• Created an issue first?
• Registered it in /packages/base/runners.json?
• Added it to /README.md?
• Included one test that runs baseline.spec.vue?
• Added and updated documentation?
• Included a recipe folder with properly building quasar project?

Does this PR introduce a breaking change? (check one)

• Yes
• No

If yes, please describe the impact and migration path for existing applications:

The PR fulfills these requirements:

• It's submitted to the dev branch and not the master branch
• When resolving a specific issue, it's referenced in the PR's title (e.g. fix: #xxx[,#xxx], where "xxx" is the issue number)
• It's been tested on Windows
• It's been tested on Linux
• It's been tested on MacOS
• Any necessary documentation has been added or updated in the docs (for faster update click on "Suggest an edit on GitHub" at bottom of page) or explained in the PR's description.

If adding a new feature, the PR's description includes:

• A convincing reason for adding this feature (to avoid wasting your time, it's best to open a suggestion issue first and wait for approval before working on it)

Other information:

I have no idea what I'm doing but I'm trying

[Copilot]

Pull request overview

This PR updates Cypress to version 15 and Vitest to version 4 across multiple test applications and packages in the monorepo. The changes ensure compatibility with the latest major versions of these testing frameworks while maintaining backward compatibility through peer dependency ranges.

Changes:

• Upgraded Cypress from v13/v14 to v15.9.0 across test applications and the e2e-cypress package
• Upgraded Vitest and @vitest/ui from v3 to v4.0.18 in test-vite-app-v2 and unit-vitest package
• Updated peer dependencies to include new major version ranges (^15.0.0 for Cypress, ^4.0.0 for Vitest)
• Bumped @quasar/app-vite from 2.3.0 to 2.4.0 in test-vite-app-v2

Reviewed changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
test-webpack-app-v4/package.json	Updated Cypress dependency from ^14.2.1 to ^15.9.0
test-vue-cli/cypress-component-test/package.json	Updated Cypress dependency from ^13.4.0 to ^15.9.0
test-vite-app-v2/package.json	Updated Cypress to ^15.9.0, Vitest and @vitest/ui to ^4.0.18, and @quasar/app-vite to ^2.4.0
packages/unit-vitest/package.json	Updated Vitest and @vitest/ui to ^4.0.18 in devDependencies, added ^4.0.0 to peer dependency ranges
packages/e2e-cypress/package.json	Updated Cypress to ^15.9.0 in devDependencies, added ^15.0.0 to peer dependency range

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