Revert "Clone github/rest-api-description during Codespace pre-build" (#52810)

.devcontainer/devcontainer.json

@@ -59,9 +59,6 @@
     // Use 'postCreateCommand' to run commands after the container is created.
     "postCreateCommand": "npm ci",
 
-    // Use 'updateContentCommand' to run commands to be included in Codespace pre-builds
-    "updateContentCommand": "git clone https://github.com/github/rest-api-description.git",
-
     // Comment out connect as root instead. More info: https://aka.ms/vscode-remote/containers/non-root.
     "remoteUser": "node",