build(deps): bump clean-css from 5.2.2 to 5.2.3 in /src

Bumps [clean-css](https://github.com/clean-css/clean-css) from 5.2.2 to 5.2.3.
- [Release notes](https://github.com/clean-css/clean-css/releases)
- [Changelog](https://github.com/clean-css/clean-css/blob/master/History.md)
- [Commits](https://github.com/clean-css/clean-css/compare/v5.2.2...v5.2.3)

---
updated-dependencies:
- dependency-name: clean-css
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

src/package-lock.json

@@ -1333,9 +1333,9 @@
       "optional": true
     },
     "clean-css": {
-      "version": "5.2.2",
-      "resolved": "https://registry.npmjs.org/clean-css/-/clean-css-5.2.2.tgz",
-      "integrity": "sha512-/eR8ru5zyxKzpBLv9YZvMXgTSSQn7AdkMItMYynsFgGwTveCRVam9IUPFloE85B4vAIj05IuKmmEoV7/AQjT0w==",
+      "version": "5.2.3",
+      "resolved": "https://registry.npmjs.org/clean-css/-/clean-css-5.2.3.tgz",
+      "integrity": "sha512-qjywD7LvpZJ5+E16lf00GnMVUX5TEVBcKW1/vtGPgAerHwRwE4JP4p1Y40zbLnup2ZfWsd30P2bHdoAKH93XxA==",
       "requires": {
         "source-map": "~0.6.0"
       }

src/package.json

@@ -31,7 +31,7 @@
   ],
   "dependencies": {
     "async": "^3.2.2",
-    "clean-css": "^5.2.2",
+    "clean-css": "^5.2.3",
     "cookie-parser": "^1.4.6",
     "cross-spawn": "^7.0.3",
     "ejs": "^3.1.6",