Excel export option missing in dashboard

[leo-schick]

New excel feature #22006 was added in 2.1.0, but the export option is not available in dashboards.

How to reproduce the bug

1. Go to Dashboard
2. Click on '....'
3. Open "Download
4. See that there is no "Export to Excel" option

Screenshots

Download menu in dashboards:

Download menu in charts:

Environment

• superset version: 2.1.0

Checklist

Make sure to follow these steps before submitting your issue - thank you!

• I have checked the superset logs for python stacktraces and included it here as text if there are any.
• I have reproduced the issue with at least the latest released version of superset.
• I have checked the issue tracker for the same issue and I haven't found one similar.

[rusackas]

Pinging @igorsinc here in case you have the wherewithal to take this on as an add-on to your prior work 🤞

I'm on the fence as to whether this qualifies as a bug (and should stay open) or is a feature request (and should be moved to DIscussions). ¯\_(ツ)_/¯