chore: set Vitest reporter for github actions (#18722)

test failures show up really bad now, minimal is way better for github actions

vitest.config.js

@@ -28,7 +28,7 @@ export default defineConfig({
 	},
 	test: {
 		dir: '.',
-		reporters: ['dot'],
+		reporters: process.env.GITHUB_ACTIONS === 'true' ? ['minimal'] : ['dot'],
 		// A handful of dev-mode tests trigger Svelte's `effect_update_depth_exceeded`
 		// guard, which involves ~1000 Error objects per flush for stack tracking —
 		// slow enough under vitest 4's deeper async stacks (and CI's slower workers)