Build(deps-dev): Bump rollup from 4.20.0 to 4.21.1 (twbs#40775)

Bumps [rollup](https://github.com/rollup/rollup) from 4.20.0 to 4.21.1.
- [Release notes](https://github.com/rollup/rollup/releases)
- [Changelog](https://github.com/rollup/rollup/blob/master/CHANGELOG.md)
- [Commits](rollup/rollup@v4.20.0...v4.21.1)

---
updated-dependencies:
- dependency-name: rollup
  dependency-type: direct:development
  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]

package-lock.json

@@ -145,7 +145,7 @@
     "npm-run-all2": "^6.2.2",
     "postcss": "^8.4.41",
     "postcss-cli": "^11.0.0",
-    "rollup": "^4.20.0",
+    "rollup": "^4.21.1",
     "rollup-plugin-istanbul": "^5.0.0",
     "rtlcss": "^4.2.0",
     "sass": "^1.77.8",