bug: Q CLI fails to load MCP server if it contains only prompts without any registered tools

### Checks

- [x] I have searched [github.com/aws/amazon-q-developer-cli/issues](https://github.com/aws/amazon-q-developer-cli/issues?q=) and there are no duplicates of my issue
- [x] I have run `q doctor` in the affected terminal session
- [x] I have run `q restart` and replicated the issue again

### Operating system

MacOs

### Expected behaviour

When a MCP server was added to q cli configuration, it should be able to initialize the server after running q chat even if it only contains prompts

command - /prompts
output - List of prompts registered in the MCP server

### Actual behaviour

q cli isn't loading the MCP server if it doesn't contain at least one registered tool

Error:
✗ my_mcp_server has failed to load:
- Failed to retrieve result for custom tool my_mcp_server

once a dummy tool is added or the request handler is set like below then it starts working

`
server.setRequestHandler(ListToolsRequestSchema, async () => {
return {
tools: []
};
})

`

### Steps to reproduce

- Install any MCP server without registering any tools under it (only prompts)
- Configure mcp.json with the correct AWS account profile
- Start q chat
- You will see an error in the startup message that mcp server isn't loaded successfully

### Environment

```yaml

```