deps: update dependency dotenv to v18

Author: renovate-bot

benchmarks/latency-comparison/nodejs/package.json

@@ -12,7 +12,7 @@
   "dependencies": {
     "@google-cloud/spanner": "^8.0.0",
     "@types/pg": "^8.11.6",
-    "dotenv": "^17.0.0",
+    "dotenv": "^18.0.0",
     "pg": "^8.11.3",
     "testcontainers": "^12.0.0",
     "yargs": "^18.1.0"