feat(dev): Pass through configLoader option to vite createViteServer

[janis-me]

Description

(this is a draft to verify the implementation. It lacks tests)

This PR

• Upgrades vite to 6.2.0 (Mirrors chore(deps): vite 6.2.0 vitest-dev/vitest#7568)
• Passes through the vite configLoader option to all createViteServer calls
• Solves issue Support for vite ModuleRunner or other configLoader alternative vitest-dev/vitest#7552

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• It's really useful if your PR references an issue where it is discussed ahead of time. If the feature is substantial or introduces breaking changes without a discussion, PR might be closed.
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Tests

• Run the tests with pnpm test:ci.

Documentation

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Changesets

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