Bump flag-icon-css from 3.5.0 to 4.1.7

Bumps [flag-icon-css](https://github.com/lipis/flag-icons) from 3.5.0 to 4.1.7.
- [Release notes](https://github.com/lipis/flag-icons/releases)
- [Commits](https://github.com/lipis/flag-icons/commits)

---
updated-dependencies:
- dependency-name: flag-icon-css
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]

package-lock.json

@@ -77,7 +77,7 @@
     "bootstrap": "^4.5.0",
     "chart.js": "^2.9.3",
     "core-js": "^3.6.5",
-    "flag-icon-css": "^3.4.6",
+    "flag-icon-css": "^4.1.7",
     "font-awesome": "~4.7.0",
     "jquery": "^3.6.0",
     "line-awesome": "github:icons8/line-awesome",