feat(csp): allow shared assets (#10858)

Allow assers from https://mdn.github.io/shared-assets/
managed via GitHub pages in https://github.com/mdn/shared-assets

Author: fiji-flo

Diff for: libs/constants/index.js

@@ -152,14 +152,24 @@ export const CSP_DIRECTIVES = {
     "wikipedia.org",
     "upload.wikimedia.org",
 
+    // Shared assets.
+    "https://mdn.github.io/shared-assets/",
+
     // GA4.
     "https://*.google-analytics.com",
     "https://*.googletagmanager.com",
 
     "www.gstatic.com",
   ],
   "manifest-src": ["'self'"],
-  "media-src": ["'self'", "archive.org", "videos.cdn.mozilla.net"],
+  "media-src": [
+    "'self'",
+    "archive.org",
+    "videos.cdn.mozilla.net",
+
+    // Shared assets.
+    "https://mdn.github.io/shared-assets/",
+  ],
   "child-src": ["'self'"],
   "worker-src": ["'self'"],
 };