revert: revert to "feat(amazonq): add MCP server support (#7451)" (#7458)

## Problem
MCP Servers feature is broken in alpha manifest and is causing
regression to chat.

## Solution
- reverting the feature flag to enable MCP

---

- Treat all work as PUBLIC. Private `feature/x` branches will not be
squash-merged at release time.
- Your code changes must meet the guidelines in
[CONTRIBUTING.md](https://github.com/aws/aws-toolkit-vscode/blob/master/CONTRIBUTING.md#guidelines).
- License: I confirm that my contribution is made under the terms of the
Apache 2.0 license.

Author: ashishrp-aws

packages/amazonq/.changes/next-release/Feature-57661731-6180-4157-a04b-d3a8b50aa1a8.json

@@ -123,7 +123,6 @@ export async function startLanguageServer(
                 awsClientCapabilities: {
                     q: {
                         developerProfiles: true,
-                        mcp: true,
                     },
                     window: {
                         notifications: true,