Add GITHUB_COPILOT_MCP_JSON environment variable to copilot job

Author: austenstone

.github/workflows/copilot-test-tools.yml

@@ -32,7 +32,19 @@ jobs:
       - run: copilot -p "$PROMPT" --allow-all-tools --log-level debug --log-dir ~/.copilot/logs
         id: copilot
         env:
+          GITHUB_COPILOT_CLI_MODE: true  # This skips default servers
           GITHUB_COPILOT_3P_MCP_ENABLED: true
+          GITHUB_COPILOT_MCP_JSON: |
+            {
+              "mcpServers": {
+                "actions-toolkit-mcp": {
+                  "type": "local",
+                  "command": "npx",
+                  "tools": [ "*" ],
+                  "args": ["-y", "actions-toolkit-mcp"]
+                }
+              }
+            }
           GH_TOKEN: ${{ secrets.PAT }}
           PROMPT: |
             list all your tools.