chore: add updated_at to codersdk users (#13928)

* chore: add updated_at to codersdk users

cli/testdata/coder_users_list_--help.golden

@@ -8,7 +8,7 @@ USAGE:
 OPTIONS:
   -c, --column string-array (default: username,email,created_at,status)
           Columns to display in table output. Available columns: id, username,
-          email, created at, status.
+          email, created at, updated at, status.
 
   -o, --output string (default: table)
           Output format. Available formats: table, json.

cli/testdata/coder_users_list_--output_json.golden

@@ -6,6 +6,7 @@
     "name": "Test User",
     "email": "testuser@coder.com",
     "created_at": "[timestamp]",
+    "updated_at": "[timestamp]",
     "last_seen_at": "[timestamp]",
     "status": "active",
     "login_type": "password",
@@ -27,6 +28,7 @@
     "name": "",
     "email": "testuser2@coder.com",
     "created_at": "[timestamp]",
+    "updated_at": "[timestamp]",
     "last_seen_at": "[timestamp]",
     "status": "dormant",
     "login_type": "password",