chore: Use UbuntuMono

lib/pages/chat/input_bar.dart

@@ -238,7 +238,7 @@ class InputBar extends StatelessWidget {
             children: [
               Text(
                 commandExample(command),
-                style: const TextStyle(fontFamily: 'monospace'),
+                style: const TextStyle(fontFamily: 'UbuntuMono'),
               ),
               Text(
                 hint,
@@ -258,7 +258,7 @@ class InputBar extends StatelessWidget {
         waitDuration: const Duration(days: 1), // don't show on hover
         child: Container(
           padding: padding,
-          child: Text(label, style: const TextStyle(fontFamily: 'monospace')),
+          child: Text(label, style: const TextStyle(fontFamily: 'UbuntuMono')),
         ),
       );
     }

lib/pages/settings_security/settings_security_view.dart

@@ -102,7 +102,7 @@ class SettingsSecurityView extends StatelessWidget {
                     leading: const Icon(Icons.vpn_key_outlined),
                     subtitle: SelectableText(
                       Matrix.of(context).client.fingerprintKey.beautified,
-                      style: const TextStyle(fontFamily: 'monospace'),
+                      style: const TextStyle(fontFamily: 'UbuntuMono'),
                     ),
                   ),
                   if (capabilities?.mChangePassword?.enabled != false ||