[desk-tool] Fix message when unpublishing a document.

[microbit-matt-hillsdon]

Type of change (check at least one)

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation (fix or update to documentation)
• Maintenance
• Other, please describe:

Does this change require a documentation update? (Check one)

• Yes
• No

Current behavior

Message says "A draft have been created" which doesn't make sense.

Description

Message fixed.

Note for release

• Fix typo in snackbar message when unpublishing a document.

Checklist

• I have read the Contributing Guidelines
• The PR title includes a link to the relevant issue
• The PR title is appropriately formatted: [some-package] PR title (#123)
• The code is linted
• The test suite is passing
• Corresponding changes to the documentation have been made

[vercel]

This pull request is being automatically deployed with Vercel (learn more).
To see the status of your deployment, click below or on the icon next to each commit.

🔍 Inspect: https://vercel.com/sanity-io/test-studio/dg4i1txhz
✅ Preview: https://test-studio-git-fork-microbit-matt-hillsdon-unpublish-typo.sanity-io.vercel.app

[rexxars]

Thanks!