chore(deps): update dependency turbo to v2.8.20

Author: renovate[bot]

generator-prisma-client/nextjs-starter-webpack-turborepo/package.json

@@ -14,7 +14,7 @@
   },
   "devDependencies": {
     "prettier": "3.8.1",
-    "turbo": "2.8.19"
+    "turbo": "2.8.20"
   },
   "engines": {
     "node": "24.4.0"