fix: upgrade prom-client from 15.1.0 to 15.1.2

Snyk has created this PR to upgrade prom-client from 15.1.0 to 15.1.2.

See this package in npm:
https://www.npmjs.com/package/prom-client

See this project in Snyk:
https://app.snyk.io/org/blambeau/project/caaa6c36-8e23-44d6-bd36-fb7ca39e8a59?utm_source=github&utm_medium=referral&page=upgrade-pr

package.json

@@ -79,7 +79,7 @@
     "express": "^4.19.2",
     "express-prom-bundle": "^6.6.0",
     "finitio": "^1.3.7",
-    "prom-client": "^15.1.0",
+    "prom-client": "^15.1.2",
     "regenerator-runtime": "^0.14.1",
     "uuid": "^9.0.1",
     "yaml": "^2.4.2"