mate.marco: 1.20.2 -> 1.21.0 (#43175)

Semi-automatic update generated by https://github.com/ryantm/nixpkgs-update tools.

This update was made based on information from https://repology.org/metapackage/marco/versions.

These checks were done:

- built on NixOS
- Warning: no invocation of /nix/store/105g04v1faqwfb457slg5igkwsi9qqdf-marco-1.21.0/bin/marco-message had a zero exit code or showed the expected version
- Warning: no invocation of /nix/store/105g04v1faqwfb457slg5igkwsi9qqdf-marco-1.21.0/bin/marco-window-demo had a zero exit code or showed the expected version
- /nix/store/105g04v1faqwfb457slg5igkwsi9qqdf-marco-1.21.0/bin/marco passed the binary check.
- Warning: no invocation of /nix/store/105g04v1faqwfb457slg5igkwsi9qqdf-marco-1.21.0/bin/marco-theme-viewer had a zero exit code or showed the expected version
- Warning: no invocation of /nix/store/105g04v1faqwfb457slg5igkwsi9qqdf-marco-1.21.0/bin/.marco-message-wrapped had a zero exit code or showed the expected version
- Warning: no invocation of /nix/store/105g04v1faqwfb457slg5igkwsi9qqdf-marco-1.21.0/bin/.marco-window-demo-wrapped had a zero exit code or showed the expected version
- /nix/store/105g04v1faqwfb457slg5igkwsi9qqdf-marco-1.21.0/bin/.marco-wrapped passed the binary check.
- Warning: no invocation of /nix/store/105g04v1faqwfb457slg5igkwsi9qqdf-marco-1.21.0/bin/.marco-theme-viewer-wrapped had a zero exit code or showed the expected version
- 2 of 8 passed binary check by having a zero exit code.
- 0 of 8 passed binary check by having the new version present in output.
- found 1.21.0 with grep in /nix/store/105g04v1faqwfb457slg5igkwsi9qqdf-marco-1.21.0
- directory tree listing: https://gist.github.com/7234306294e99b33fef6a86358544611
- du listing: https://gist.github.com/8c742fd13a9c7ded57bc11be9c669b95