Bump highlight.js from 9.15.8 to 9.18.5 in /WebUI

Bumps [highlight.js](https://github.com/highlightjs/highlight.js) from 9.15.8 to 9.18.5.
- [Release notes](https://github.com/highlightjs/highlight.js/releases)
- [Changelog](https://github.com/highlightjs/highlight.js/blob/9.18.5/CHANGES.md)
- [Commits](highlightjs/highlight.js@9.15.8...9.18.5)

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

Author: dependabot[bot]

WebUI/yarn.lock

@@ -4903,9 +4903,9 @@ hex-color-regex@^1.1.0:
   integrity sha512-l9sfDFsuqtOqKDsQdqrMRk0U85RZc0RtOR9yPI7mRVOa4FsR/BVnZ0shmQRM96Ji99kYZP/7hn1cedc1+ApsTQ==
 
 highlight.js@^9.6.0:
-  version "9.18.3"
-  resolved "https://registry.yarnpkg.com/highlight.js/-/highlight.js-9.18.3.tgz#a1a0a2028d5e3149e2380f8a865ee8516703d634"
-  integrity sha512-zBZAmhSupHIl5sITeMqIJnYCDfAEc3Gdkqj65wC1lpI468MMQeeQkhcIAvk+RylAkxrCcI9xy9piHiXeQ1BdzQ==
+  version "9.18.5"
+  resolved "https://registry.yarnpkg.com/highlight.js/-/highlight.js-9.18.5.tgz#d18a359867f378c138d6819edfc2a8acd5f29825"
+  integrity sha512-a5bFyofd/BHCX52/8i8uJkjr9DYwXIPnM/plwI6W7ezItLGqzt7X2G2nXuYSfsIJdkwwj/g9DG1LkcGJI/dDoA==
 
 hmac-drbg@^1.0.0:
   version "1.0.1"