Bump rollup from 2.19.0 to 2.21.0

Bumps [rollup](https://github.com/rollup/rollup) from 2.19.0 to 2.21.0.
- [Release notes](https://github.com/rollup/rollup/releases)
- [Changelog](https://github.com/rollup/rollup/blob/master/CHANGELOG.md)
- [Commits](https://github.com/rollup/rollup/compare/v2.19.0...v2.21.0)

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

package-lock.json

@@ -12280,9 +12280,9 @@
       }
     },
     "rollup": {
-      "version": "2.19.0",
-      "resolved": "https://registry.npmjs.org/rollup/-/rollup-2.19.0.tgz",
-      "integrity": "sha512-nny5Vs4jwY3vbQAXgOyU4ZDZqLvMKm/umnsVry/demVL6ve8ke1XhdpYE0eiWencASmx/qFPw6pP8P7MLJl9XA==",
+      "version": "2.21.0",
+      "resolved": "https://registry.npmjs.org/rollup/-/rollup-2.21.0.tgz",
+      "integrity": "sha512-BEGgy+wSzux7Ycq58pRiWEOBZaXRXTuvzl1gsm7gqmsAHxkWf9nyA5V2LN9fGSHhhDQd0/C13iRzSh4bbIpWZQ==",
       "dev": true,
       "requires": {
         "fsevents": "~2.1.2"