feat: upgrade to Biome 2.4 with Tailwind support

[bgub]

Biome 2.3.x added support for parsing Tailwind v4 directives (biomejs/biome#7164).

In the past, we disabled the "noUnknownAtRules" linting rule entirely (#83059). Now we should be able to re-enable it!

[ijjk]

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[Copilot]

Pull request overview

This PR upgrades Biome from version 2.2.0 to 2.4.2 across all create-next-app templates to enable Tailwind v4 directive parsing support. The upgrade allows re-enabling the "noUnknownAtRules" linting rule that was previously disabled to work around Biome's lack of Tailwind support.

Changes:

• Upgraded @biomejs/biome dependency from 2.2.0 to 2.4.2
• Updated schema URLs in all biome.json configuration files to version 2.4.2
• Added css.parser.tailwindDirectives configuration to all Tailwind templates (-tw suffix)
• Removed suspicious.noUnknownAtRules: "off" override from Tailwind templates

Reviewed changes

Copilot reviewed 20 out of 20 changed files in this pull request and generated 1 comment.

File	Description
packages/create-next-app/templates/index.ts	Updates Biome dependency to 2.4.2
test/integration/create-next-app/snapshots/biome-config.test.ts.snap	Updates test snapshot with new schema version
packages/create-next-app/templates/*/biome.json (all templates)	Updates schema URL to 2.4.2
packages/create-next-app/templates/-tw/biome.json (Tailwind templates)	Adds tailwindDirectives parser setting and removes noUnknownAtRules override

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