deps(deps): bump @modelcontextprotocol/sdk in the mcp-sdk group

Bumps the mcp-sdk group with 1 update: [@modelcontextprotocol/sdk](https://github.com/modelcontextprotocol/typescript-sdk).


Updates `@modelcontextprotocol/sdk` from 1.17.4 to 1.21.0
- [Release notes](https://github.com/modelcontextprotocol/typescript-sdk/releases)
- [Commits](modelcontextprotocol/typescript-sdk@1.17.4...1.21.0)

---
updated-dependencies:
- dependency-name: "@modelcontextprotocol/sdk"
  dependency-version: 1.21.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
  dependency-group: mcp-sdk
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

package-lock.json

@@ -23,7 +23,7 @@
   "author": "Countly MCP Server",
   "license": "MIT",
   "dependencies": {
-    "@modelcontextprotocol/sdk": "^1.17.4",
+    "@modelcontextprotocol/sdk": "^1.21.0",
     "axios": "^1.6.0",
     "dotenv": "^17.2.2"
   },