Bump prismjs from 1.17.1 to 1.21.0 in /site (#5250)

Bumps [prismjs](https://github.com/PrismJS/prism) from 1.17.1 to 1.21.0.
- [Release notes](https://github.com/PrismJS/prism/releases)
- [Changelog](https://github.com/PrismJS/prism/blob/master/CHANGELOG.md)
- [Commits](https://github.com/PrismJS/prism/compare/v1.17.1...v1.21.0)

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

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

site/package-lock.json

@@ -1573,9 +1573,9 @@
       }
     },
     "clipboard": {
-      "version": "2.0.4",
-      "resolved": "https://registry.npmjs.org/clipboard/-/clipboard-2.0.4.tgz",
-      "integrity": "sha512-Vw26VSLRpJfBofiVaFb/I8PVfdI1OxKcYShe6fm0sP/DtmiWQNCjhM/okTvdCo0G+lMMm1rMYbk4IK4x1X+kgQ==",
+      "version": "2.0.6",
+      "resolved": "https://registry.npmjs.org/clipboard/-/clipboard-2.0.6.tgz",
+      "integrity": "sha512-g5zbiixBRk/wyKakSwCKd7vQXDjFnAMGHoEyBogG/bw9kTD9GvdAvaoRR1ALcEzt3pVKxZR0pViekPMIS0QyGg==",
       "optional": true,
       "requires": {
         "good-listener": "^1.2.2",
@@ -3170,9 +3170,9 @@
       "integrity": "sha512-plS7uY0WWiTBwWZs9KM3M88ZxHWKbrbMUDf52CPum6BqAxiLmKROmaTnmhXtv0krQ0l0HRLcFS8JDwOFyPt/OQ=="
     },
     "prismjs": {
-      "version": "1.17.1",
-      "resolved": "https://registry.npmjs.org/prismjs/-/prismjs-1.17.1.tgz",
-      "integrity": "sha512-PrEDJAFdUGbOP6xK/UsfkC5ghJsPJviKgnQOoxaDbBjwc8op68Quupwt1DeAFoG8GImPhiKXAvvsH7wDSLsu1Q==",
+      "version": "1.21.0",
+      "resolved": "https://registry.npmjs.org/prismjs/-/prismjs-1.21.0.tgz",
+      "integrity": "sha512-uGdSIu1nk3kej2iZsLyDoJ7e9bnPzIgY0naW/HdknGj61zScaprVEVGHrPoXqI+M9sP0NDnTK2jpkvmldpuqDw==",
       "requires": {
         "clipboard": "^2.0.0"
       }

site/package.json

@@ -25,7 +25,7 @@
     "pg": "^7.12.1",
     "polka": "^1.0.0-next.9",
     "prism-svelte": "^0.4.3",
-    "prismjs": "^1.17.1",
+    "prismjs": "^1.21.0",
     "sirv": "^1.0.0-next.2",
     "yootils": "0.0.16"
   },