Bump rollup from 3.20.7 to 3.21.0

Bumps [rollup](https://github.com/rollup/rollup) from 3.20.7 to 3.21.0.
- [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/v3.20.7...v3.21.0)

---
updated-dependencies:
- dependency-name: rollup
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

package-lock.json

@@ -31,7 +31,7 @@
         "postcss": "^8.4.23",
         "postcss-cli": "^10.1.0",
         "postcss-understrap-palette-generator": "git+https://github.com/understrap/postcss-understrap-palette-generator.git",
-        "rollup": "^3.20.7",
+        "rollup": "^3.21.0",
         "sass": "^1.62.0",
         "terser": "^5.17.1"
       },
@@ -5281,9 +5281,9 @@
       }
     },
     "node_modules/rollup": {
-      "version": "3.20.7",
-      "resolved": "https://registry.npmjs.org/rollup/-/rollup-3.20.7.tgz",
-      "integrity": "sha512-P7E2zezKSLhWnTz46XxjSmInrbOCiul1yf+kJccMxT56vxjHwCbDfoLbiqFgu+WQoo9ij2PkraYaBstgB2prBA==",
+      "version": "3.21.0",
+      "resolved": "https://registry.npmjs.org/rollup/-/rollup-3.21.0.tgz",
+      "integrity": "sha512-ANPhVcyeHvYdQMUyCbczy33nbLzI7RzrBje4uvNiTDJGIMtlKoOStmympwr9OtS1LZxiDmE2wvxHyVhoLtf1KQ==",
       "dev": true,
       "bin": {
         "rollup": "dist/bin/rollup"

package.json

@@ -76,7 +76,7 @@
     "postcss": "^8.4.23",
     "postcss-cli": "^10.1.0",
     "postcss-understrap-palette-generator": "git+https://github.com/understrap/postcss-understrap-palette-generator.git",
-    "rollup": "^3.20.7",
+    "rollup": "^3.21.0",
     "sass": "^1.62.0",
     "terser": "^5.17.1"
   }