Common-utils : Remove unwanted extension (#173)

* extension - cleanup

* version bump

src/common-utils/devcontainer-feature.json

 {
     "id": "common-utils",
-    "version": "1.1.0",
+    "version": "1.1.1",
     "name": "Common Debian Utilities",
     "documentationURL": "https://github.com/devcontainers/features/tree/main/src/common-utils",
     "description": "Installs a set of common command line utilities, Oh My Zsh!, and sets up a non-root user.",
@@ -54,12 +54,5 @@
             "default": false,
             "description": "Add packages from non-free Debian repository?"
         }
-    },
-    "customizations": {
-        "vscode": {
-            "extensions": [
-                "ms-dotnettools.csharp"
-            ]
-        }
     }
 }