fix: extensions/markdown-language-features/package.json & extensions/…

…markdown-language-features/yarn.lock to reduce vulnerabilities

The following vulnerabilities are fixed with an upgrade:
- https://snyk.io/vuln/SNYK-JS-DOMPURIFY-7984421

extensions/markdown-language-features/package.json

@@ -499,7 +499,7 @@
   },
   "dependencies": {
     "@vscode/extension-telemetry": "0.4.10",
-    "dompurify": "^2.3.3",
+    "dompurify": "^2.5.4",
     "highlight.js": "^11.4.0",
     "markdown-it": "^12.3.2",
     "markdown-it-front-matter": "^0.2.1",

extensions/markdown-language-features/yarn.lock

@@ -64,10 +64,10 @@ argparse@^2.0.1:
   resolved "https://registry.yarnpkg.com/argparse/-/argparse-2.0.1.tgz#246f50f3ca78a3240f6c997e8a9bd1eac49e4b38"
   integrity sha512-8+9WqebbFzpX9OR+Wa6O29asIogeRMzcGtAINdpMHHyAg10f05aSFVBbcEqGf/PXw1EjAZ+q2/bEBg3DvurK3Q==
 
-dompurify@^2.3.3:
-  version "2.3.3"
-  resolved "https://registry.yarnpkg.com/dompurify/-/dompurify-2.3.3.tgz#c1af3eb88be47324432964d8abc75cf4b98d634c"
-  integrity sha512-dqnqRkPMAjOZE0FogZ+ceJNM2dZ3V/yNOuFB7+39qpO93hHhfRpHw3heYQC7DPK9FqbQTfBKUJhiSfz4MvXYwg==
+dompurify@^2.5.4:
+  version "2.5.6"
+  resolved "https://registry.yarnpkg.com/dompurify/-/dompurify-2.5.6.tgz#8402b501611eaa7fb3786072297fcbe2787f8592"
+  integrity sha512-zUTaUBO8pY4+iJMPE1B9XlO2tXVYIcEA4SNGtvDELzTSCQO7RzH+j7S180BmhmJId78lqGU2z19vgVx2Sxs/PQ==
 
 entities@~2.1.0:
   version "2.1.0"