chore(deps): bump prom-client from 14.0.1 to 15.1.1

Bumps [prom-client](https://github.com/siimon/prom-client) from 14.0.1 to 15.1.1.
- [Release notes](https://github.com/siimon/prom-client/releases)
- [Changelog](https://github.com/siimon/prom-client/blob/master/CHANGELOG.md)
- [Commits](siimon/prom-client@v14.0.1...v15.1.1)

---
updated-dependencies:
- dependency-name: prom-client
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

package.json

@@ -122,7 +122,7 @@
     "opossum": "^8.1.3",
     "opossum-prometheus": "^0.3.0",
     "pidusage": "^3.0.2",
-    "prom-client": "^14.0.1",
+    "prom-client": "^15.1.1",
     "prop-types": "^15.7.2",
     "react": "^16.14.0",
     "react-dom": "^16.14.0",