ci: stabilize vitest runs

vitest.config.ts

@@ -3,6 +3,7 @@ import { fileURLToPath } from "node:url";
 import { defineConfig } from "vitest/config";
 
 const repoRoot = path.dirname(fileURLToPath(import.meta.url));
+const isCI = process.env.CI === "true" || process.env.GITHUB_ACTIONS === "true";
 
 export default defineConfig({
   resolve: {
@@ -11,8 +12,10 @@ export default defineConfig({
     },
   },
   test: {
-    testTimeout: 30_000,
-    hookTimeout: 60_000,
+    testTimeout: 60_000,
+    hookTimeout: 120_000,
+    pool: "forks",
+    maxWorkers: isCI ? 3 : 4,
     include: [
       "src/**/*.test.ts",
       "extensions/**/*.test.ts",