feat(vitest-config)!: Return the plain config object

Returning the plain config object instead of the result of defineConfig,
allows for simpler modification/adaptation of the result.

BREAKING CHANGE: You must wrap the result in defineConfig yourself now.

packages/vitest-config/src-tests-folder-config.ts

@@ -1,12 +1,10 @@
-import { defineConfig } from 'vitest/config'
-
 export const srcTestFolderConfig = function (baseUrl: string) {
-	return defineConfig({
+	return {
 		test: {
 			alias: {
 				'@/': decodeURI(new URL('./src/', baseUrl).pathname)
 			},
 			dir: 'tests'
 		}
-	})
+	}
 }