bump(convex): 8b01557d → 9b213840 (#5568)

Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>

.claude-plugin/marketplace.json

@@ -1084,7 +1084,7 @@
       "source": {
         "source": "url",
         "url": "https://github.com/get-convex/convex-backend-skill.git",
-        "sha": "8b01557dc3dd2e390ad090025c67f5e022bd21ad"
+        "sha": "9b213840f870e546de7bef1fbc3ae98793099ca5"
       },
       "homepage": "https://github.com/get-convex/convex-backend-skill",
       "keywords": [