fix(copilot): simplify setup — Java 21 in workflow, download+start in MCP config

Removed comments explaining the workflow and installation steps.

Author: sunix

.github/workflows/copilot-setup-steps.yml

@@ -1,9 +1,3 @@
-# This workflow runs the setup steps that the GitHub Copilot coding agent
-# needs before it can start MCP servers.
-#
-# It downloads and installs the jdtls-mcp server to a stable cache location
-# (~/.cache/jdtls-mcp/current/) so that the MCP configuration can reference
-# a fixed path without needing to download anything at MCP startup time.
 on:
   workflow_dispatch:
 
@@ -20,7 +14,3 @@ jobs:
         with:
           distribution: temurin
           java-version: '21'
-
-      - name: Install jdtls-mcp
-        run: |
-          bash <(curl -fsSL https://raw.githubusercontent.com/sunix/jdtls-mcp/main/scripts/install.sh)