MCP/DBHub: Update to 0.11.6 for compatibility with Node.js 25

  /path/to/node_modules/buffer-equal-constant-time/index.js:37
  var origSlowBufEqual = SlowBuffer.prototype.equal;
                                    ^
  TypeError: Cannot read properties of undefined (reading 'prototype')

Author: amotl

framework/mcp/example_dbhub.py

@@ -14,7 +14,7 @@
     command="npx",
     args=[
         "-y",
-        "@bytebase/dbhub@0.3.1",
+        "@bytebase/dbhub@0.11.6",
         "--transport=stdio",
         #"--transport=sse",
         #"--port=8080",