Don't try to install the CLI on the first step

We already install it for you in the prebuild, so there's no need for this command.

This solves a problem where you get unnecessary alerts from the extension:
- first time you're on the step, you're told the CLI is already installed.
- subsequent times you click on the step, you're shown an error "Already installing CLI".

We'd like to get rid of both of these warnings.

Author: elenatanasoiu

.tours/codeql-tutorial.tour

@@ -4,11 +4,8 @@
   "isPrimary": true,
   "steps": [
     {
-      "description": "The CodeQL extension uses the CodeQL CLI to compile and run queries. It automatically manages access to the executable of the CLI for you.\n\nClick 'Next' when you see a popup notification telling you that the CLI has been installed or updated.",
-      "commands": [
-        "codeQL.checkForUpdatesToCLI"
-      ],
-      "title": "Set up extension"
+      "description": "First let's talk about the CodeQL CLI.\n\nThe CodeQL extension uses the CodeQL CLI to compile and run queries. It automatically manages access to the executable of the CLI for you.\n\nWe've already set it up to use in this tutorial. To learn more about the CodeQL CLI, see [the docs](https://codeql.github.com/).",
+      "title": "The CodeQL CLI"
     },
     {
       "directory": ".tours/codeql-tutorial-database",