Clean up devcontainer.json: remove duplicate keys and invalid setting (#39)

Agent-Logs-Url: https://github.com/skills/create-applications-with-the-copilot-cli/sessions/473b6ab6-017a-4577-af6c-3de341b4f1ac

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: arilivigni <4140343+arilivigni@users.noreply.github.com>

Author: Copilot

.devcontainer/devcontainer.json

@@ -41,13 +41,10 @@
         "workbench.layoutControl.enabled": false,
         "workbench.layoutControl.type": "hidden",
         "workbench.panel.opensMaximized": "always",
-        "workbench.startupEditor": "none",
         "workbench.tips.enabled": false,
         "window.openFilesInNewWindow": "off",
         "terminal.integrated.automationProfile.linux": null,
-        "workbench.action.terminal.focus": true,
-        "terminal.integrated.showOnStartup": "always",
-        "workbench.panel.opensMaximized": "always"
+        "terminal.integrated.showOnStartup": "always"
       }
     }
   },