Bump express from 4.18.2 to 4.19.2 in /tools/st-prom-exporter

Bumps [express](https://github.com/expressjs/express) from 4.18.2 to 4.19.2.
- [Release notes](https://github.com/expressjs/express/releases)
- [Changelog](https://github.com/expressjs/express/blob/master/History.md)
- [Commits](expressjs/express@4.18.2...4.19.2)

---
updated-dependencies:
- dependency-name: express
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

tools/st-prom-exporter/package.json

@@ -12,7 +12,7 @@
   "license": "Unicode-3.0",
   "dependencies": {
     "bent": "^7.3.10",
-    "express": "^4.18.2",
+    "express": "^4.19.2",
     "prom-client": "^12.0.0"
   },
   "repository": {