Remove crestapps-orchardcore plugin from marketplace.json

Removed the 'crestapps-orchardcore' plugin details from the marketplace configuration.

Author: MikeAlhayek

.github/plugin/marketplace.json

@@ -77,29 +77,6 @@
       "description": "Build applications with the GitHub Copilot SDK across multiple programming languages. Includes comprehensive instructions for C#, Go, Node.js/TypeScript, and Python to help you create AI-powered applications.",
       "version": "1.0.0"
     },
-    {
-      "name": "crestapps-orchardcore",
-      "description": "Orchard Core skills for GitHub Copilot CLI backed by CrestApps.AgentSkills.",
-      "version": "1.0.0",
-      "author": {
-        "name": "CrestApps",
-        "url": "https://github.com/CrestApps"
-      },
-      "homepage": "https://github.com/CrestApps/CrestApps.AgentSkills/tree/main/plugins/crestapps-orchardcore",
-      "keywords": [
-        "orchard-core",
-        "copilot-cli",
-        "skills",
-        "dotnet"
-      ],
-      "license": "MIT",
-      "repository": "https://github.com/CrestApps/CrestApps.AgentSkills",
-      "source": {
-        "source": "github",
-        "repo": "CrestApps/CrestApps.AgentSkills",
-        "path": "plugins/crestapps-orchardcore"
-      }
-    },
     {
       "name": "csharp-dotnet-development",
       "source": "csharp-dotnet-development",