[FIX] mail: stop prompting guests for commands as they will not work

While we do want to support at least some commands for guests, they
currently aren't supported. This commit stops prompting guests for
commands as they will not work.

X-original-commit: dbad80dbeec5bd76c27dc9dd4b2cb7daaf97b939
Part-of: odoo/odoo#76616

addons/mail/static/src/models/messaging_initializer/messaging_initializer.js

@@ -108,7 +108,10 @@ function factory(dependencies) {
             }
             // various suggestions in no particular order
             this._initCannedResponses(shortcodes);
-            this._initCommands();
+            // FIXME: guests should have (at least some) commands available
+            if (!this.messaging.isCurrentUserGuest) {
+                this._initCommands();
+            }
             // channels when the rest of messaging is ready
             await this.async(() => this._initChannels(channels));
             // failures after channels