chore: mark media-tracking change as patch

The change is a user-facing behaviour fix in a published package, matching
the 'patch' type used for comparable plugin fixes, rather than 'none'.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

Author: matus-tomlein

common/changes/@snowplow/browser-plugin-media-tracking/media-element-empty-src_2026-09-09-10-30.json

@@ -2,7 +2,7 @@
   "changes": [
     {
       "comment": "Omit the media_element entity while the element has no source, instead of emitting an empty currentSrc that fails schema validation",
-      "type": "none",
+      "type": "patch",
       "packageName": "@snowplow/browser-plugin-media-tracking"
     }
   ],