Bump countup.js from 2.8.2 to 2.9.0 in /webapp (#4445)

Bumps [countup.js](https://github.com/inorganik/countUp.js) from 2.8.2 to 2.9.0.
- [Release notes](https://github.com/inorganik/countUp.js/releases)
- [Commits](inorganik/countUp.js@v2.8.2...v2.9.0)

---
updated-dependencies:
- dependency-name: countup.js
  dependency-version: 2.9.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

webapp/package-lock.json

@@ -91,7 +91,7 @@
     "@vaadin/vaadin-date-picker": "4.4.1",
     "@vaadin/vaadin-grid": "5.7.13",
     "@webcomponents/webcomponentsjs": "2.8.0",
-    "countup.js": "2.8.2",
+    "countup.js": "2.9.0",
     "pluralize": "8.0.0"
   }
 }