spaceless is deprecated since Twig 2.7, use apply spaceless instead and Drupal 9 updates

Just checking if anyone has contacted the Security Team → to review the patch, so that the project can get a new maintainer and the patch can be released? The theme is (still) stuck in limbo until this happens.

I've just reported this to the Security Team to try to get some attention/progress made: https://security.drupal.org/node/178491

I am removing the security tag because this issue is a deprecation update. There doesn't seem to be a security bug here.

#19 doesn't work. It is giving issues when core is upgraded to 10.

#19 got applied properly, Cog got compatible with 9.5.11, the theme version also got updated. But on core upgrade to 10. It is giving lot of issues. Hence, moving this to needs work.