Bump handlebars from 4.7.8 to 4.7.9 in /freeciv-web

Bumps [handlebars](https://github.com/handlebars-lang/handlebars.js) from 4.7.8 to 4.7.9.
- [Release notes](https://github.com/handlebars-lang/handlebars.js/releases)
- [Changelog](https://github.com/handlebars-lang/handlebars.js/blob/v4.7.9/release-notes.md)
- [Commits](handlebars-lang/handlebars.js@v4.7.8...v4.7.9)

---
updated-dependencies:
- dependency-name: handlebars
  dependency-version: 4.7.9
  dependency-type: direct:development
...

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

Author: dependabot[bot]

freeciv-web/package-lock.json

@@ -1,6 +1,6 @@
 {
   "devDependencies": {
-    "handlebars": "^4.7.8"
+    "handlebars": "^4.7.9"
   },
   "scripts": {
     "compile-hb": "f() { ./node_modules/handlebars/bin/handlebars src/main/webapp/webclient -e hbs -f \"$1\"/hbs-templates.js --knownOnly; }; f"