CompatHelper: bump compat for DataStructures to 0.19, (keep existing compat)

[github-actions]

This pull request changes the compat entry for the DataStructures package from 0.17, 0.18 to 0.17, 0.18, 0.19.
This keeps the compat entries for earlier versions.

Note: I have not tested your package with this new compat entry.
It is your responsibility to make sure that your package tests pass before you merge this pull request.

[etpinard]

Hello to anyone working for Plotly seeing this message.

Looks like I no longer have write rights to this repo and thus cannot merge PRs like this one and make releases.

Fair enough, I'm no longer a Plotly employee. Alex Johnson gave me write rights a few years back and he's no longer a Plotly employee.

But, I'm still using Dash.jl in production as part of my job at R2, and I would find it sad to see Dash.jl go unmaintained.

[alexcjohnson]

Hey @etpinard if this is a new thing I suspect it was unintentional, Plotly had a bit of a security scare over the Nx mess and locked everything down while investigating. I'll check in with @gvwilson

[etpinard]

thank you very much @alexcjohnson @gvwilson @honda0306 !

😄 🎉 👍