Bump clean-css-cli from 5.2.0 to 5.2.1

Bumps [clean-css-cli](https://github.com/jakubpawlowicz/clean-css-cli) from 5.2.0 to 5.2.1.
- [Release notes](https://github.com/jakubpawlowicz/clean-css-cli/releases)
- [Changelog](https://github.com/jakubpawlowicz/clean-css-cli/blob/master/History.md)
- [Commits](https://github.com/jakubpawlowicz/clean-css-cli/commits)

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

package-lock.json

@@ -3980,21 +3980,21 @@
       }
     },
     "clean-css": {
-      "version": "5.1.0",
-      "resolved": "https://registry.npmjs.org/clean-css/-/clean-css-5.1.0.tgz",
-      "integrity": "sha512-98ALLW4NOhZpvUEoSc2dJO23xE4S4SXc4mLieCVFGo8DNLTFQ3gzi7msW1lqSYJeGZSF5r5+W3KF6cEnkILnFQ==",
+      "version": "5.1.1",
+      "resolved": "https://registry.npmjs.org/clean-css/-/clean-css-5.1.1.tgz",
+      "integrity": "sha512-GQ6HdEyJN0543mRTA/TkZ7RPoMXGWKq1shs9H86F2kLuixR0RI+xd4JfhJxWUW08FGKQXTKAKpVjKQXu5zkFNA==",
       "dev": true,
       "requires": {
         "source-map": "~0.6.0"
       }
     },
     "clean-css-cli": {
-      "version": "5.2.0",
-      "resolved": "https://registry.npmjs.org/clean-css-cli/-/clean-css-cli-5.2.0.tgz",
-      "integrity": "sha512-c7TQ+Lq8azYtThXtWlf0m9Iw66wBLQ0LPUJIEKHWTn8HB2tQlbqY6BMoKdgW4NJVZOYquwQrrRszTqH8NjHgTg==",
+      "version": "5.2.1",
+      "resolved": "https://registry.npmjs.org/clean-css-cli/-/clean-css-cli-5.2.1.tgz",
+      "integrity": "sha512-y+nSP8lcBWXWHqBVK1o1UQjUR/s1Xu3H7rSXtp4R03orU8gGCkmYZjwhALMww6E6JChjoshpLodV+VfjAufaHw==",
       "dev": true,
       "requires": {
-        "clean-css": "^5.1.0",
+        "clean-css": "^5.1.1",
         "commander": "7.x",
         "glob": "^7.1.6"
       },

package.json

@@ -59,7 +59,7 @@
     "buble": "^0.20.0",
     "buble-loader": "^0.5.1",
     "chaikin-smooth": "^1.0.4",
-    "clean-css-cli": "5.2.0",
+    "clean-css-cli": "5.2.1",
     "copy-webpack-plugin": "^6.0.1",
     "coveralls": "3.1.0",
     "eslint": "^7.2.0",