bump(amplitude): a393e09d → 90c0a8e6 (#4962)

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

.claude-plugin/marketplace.json

@@ -208,7 +208,7 @@
         "url": "https://github.com/amplitude/mcp-marketplace.git",
         "path": "plugins/amplitude",
         "ref": "main",
-        "sha": "a393e09d188c4e541c6e89d677f6615d73211ef6"
+        "sha": "90c0a8e658db547ab63a2210e84be07c23ce4cd0"
       },
       "description": "Use Amplitude as an expert analyst — instrument Amplitude, discover product opportunities, analyze charts, create dashboards, manage experiments, and understand users and accounts.",
       "category": "monitoring",