chore(deps): bump the rollup group with 2 updates

Bumps the rollup group with 2 updates: [rollup](https://github.com/rollup/rollup) and [rollup-plugin-import-css](https://github.com/jleeson/rollup-plugin-import-css).


Updates `rollup` from 4.24.3 to 4.28.0
- [Release notes](https://github.com/rollup/rollup/releases)
- [Changelog](https://github.com/rollup/rollup/blob/master/CHANGELOG.md)
- [Commits](rollup/rollup@v4.24.3...v4.28.0)

Updates `rollup-plugin-import-css` from 3.5.6 to 3.5.7
- [Commits](https://github.com/jleeson/rollup-plugin-import-css/commits)

---
updated-dependencies:
- dependency-name: rollup
  dependency-type: direct:development
  update-type: version-update:semver-minor
  dependency-group: rollup
- dependency-name: rollup-plugin-import-css
  dependency-type: direct:production
  update-type: version-update:semver-patch
  dependency-group: rollup
...

Signed-off-by: dependabot[bot] <[email protected]>

examples/fdc3-chart-and-grid/js-chart/package.json

@@ -21,7 +21,7 @@
   "devDependencies": {
     "http-server": "14.1.1",
     "rimraf": "6.0.1",
-    "rollup": "4.24.3",
+    "rollup": "4.28.0",
     "@rollup/plugin-commonjs": "28.0.1",
     "@rollup/plugin-node-resolve": "15.3.0"
   }

examples/fdc3-pricing-and-chat/js-chat/package.json

@@ -23,6 +23,6 @@
     "@rollup/plugin-node-resolve": "15.3.0",
     "http-server": "14.1.1",
     "rimraf": "6.0.1",
-    "rollup": "4.24.3"
+    "rollup": "4.28.0"
   }
 }

examples/fdc3-pricing-and-chat/js-pricing/package.json

@@ -22,7 +22,7 @@
     "@rollup/plugin-node-resolve": "15.3.0",
     "http-server": "14.1.1",
     "rimraf": "6.0.1",
-    "rollup": "4.24.3",
+    "rollup": "4.28.0",
     "rollup-plugin-import-css": "^3.5.0"
   }
 }