feat: treat vite config files as dev files

[smackfu]

Description

Marks the vite / vitest config files as development files so that the import/no-extraneous-dependencies rule works properly.

Motivation and Context

Without this, eslint throws an error saying any imports they use should be added to dependencies not devDependencies.

How Has This Been Tested?

Packed and installed in a repo using vitest.

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation (adding or updating documentation)
• Dependency update